diff --git a/src/archive/plugins/Bzip2ArchivePlugin.cxx b/src/archive/plugins/Bzip2ArchivePlugin.cxx
index db0d013ff..638ad84e5 100644
--- a/src/archive/plugins/Bzip2ArchivePlugin.cxx
+++ b/src/archive/plugins/Bzip2ArchivePlugin.cxx
@@ -72,7 +72,8 @@ public:
 
 	/* virtual methods from InputStream */
 	bool IsEOF() noexcept override;
-	size_t Read(void *ptr, size_t size) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
 
 private:
 	void Open();
@@ -147,7 +148,7 @@ Bzip2InputStream::FillBuffer()
 }
 
 size_t
-Bzip2InputStream::Read(void *ptr, size_t length)
+Bzip2InputStream::Read(std::unique_lock<Mutex> &, void *ptr, size_t length)
 {
 	const ScopeUnlock unlock(mutex);
 
diff --git a/src/archive/plugins/Iso9660ArchivePlugin.cxx b/src/archive/plugins/Iso9660ArchivePlugin.cxx
index a27230728..59060bd64 100644
--- a/src/archive/plugins/Iso9660ArchivePlugin.cxx
+++ b/src/archive/plugins/Iso9660ArchivePlugin.cxx
@@ -157,7 +157,8 @@ public:
 
 	/* virtual methods from InputStream */
 	bool IsEOF() noexcept override;
-	size_t Read(void *ptr, size_t size) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
 };
 
 InputStreamPtr
@@ -174,7 +175,8 @@ Iso9660ArchiveFile::OpenStream(const char *pathname,
 }
 
 size_t
-Iso9660InputStream::Read(void *ptr, size_t read_size)
+Iso9660InputStream::Read(std::unique_lock<Mutex> &,
+			 void *ptr, size_t read_size)
 {
 	const ScopeUnlock unlock(mutex);
 
diff --git a/src/archive/plugins/ZzipArchivePlugin.cxx b/src/archive/plugins/ZzipArchivePlugin.cxx
index e238dd4ba..ed41c5d2b 100644
--- a/src/archive/plugins/ZzipArchivePlugin.cxx
+++ b/src/archive/plugins/ZzipArchivePlugin.cxx
@@ -111,8 +111,9 @@ public:
 
 	/* virtual methods from InputStream */
 	bool IsEOF() noexcept override;
-	size_t Read(void *ptr, size_t size) override;
-	void Seek(offset_type offset) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
+	void Seek(std::unique_lock<Mutex> &lock, offset_type offset) override;
 };
 
 InputStreamPtr
@@ -130,7 +131,7 @@ ZzipArchiveFile::OpenStream(const char *pathname,
 }
 
 size_t
-ZzipInputStream::Read(void *ptr, size_t read_size)
+ZzipInputStream::Read(std::unique_lock<Mutex> &, void *ptr, size_t read_size)
 {
 	const ScopeUnlock unlock(mutex);
 
@@ -149,7 +150,7 @@ ZzipInputStream::IsEOF() noexcept
 }
 
 void
-ZzipInputStream::Seek(offset_type new_offset)
+ZzipInputStream::Seek(std::unique_lock<Mutex> &, offset_type new_offset)
 {
 	const ScopeUnlock unlock(mutex);
 
diff --git a/src/command/FileCommands.cxx b/src/command/FileCommands.cxx
index 448da2caf..9f040bd8b 100644
--- a/src/command/FileCommands.cxx
+++ b/src/command/FileCommands.cxx
@@ -292,9 +292,9 @@ read_stream_art(Response &r, const char *uri, size_t offset)
 	size_t read_size;
 
 	{
-		const std::lock_guard<Mutex> protect(mutex);
-		is->Seek(offset);
-		read_size = is->Read(&buffer, CHUNK_SIZE);
+		std::unique_lock<Mutex> lock(mutex);
+		is->Seek(lock, offset);
+		read_size = is->Read(lock, &buffer, CHUNK_SIZE);
 	}
 
 	r.Format("size: %" PRIoffset "\n"
diff --git a/src/command/FingerprintCommands.cxx b/src/command/FingerprintCommands.cxx
index be5aa3f2c..295795c95 100644
--- a/src/command/FingerprintCommands.cxx
+++ b/src/command/FingerprintCommands.cxx
@@ -305,7 +305,7 @@ GetChromaprintCommand::Read(InputStream &is, void *buffer, size_t length)
 		cond.wait(lock);
 	}
 
-	return is.Read(buffer, length);
+	return is.Read(lock, buffer, length);
 }
 
 CommandResult
diff --git a/src/decoder/Bridge.cxx b/src/decoder/Bridge.cxx
index 28e0d0104..065da259d 100644
--- a/src/decoder/Bridge.cxx
+++ b/src/decoder/Bridge.cxx
@@ -403,7 +403,7 @@ try {
 		dc.cond.wait(lock);
 	}
 
-	size_t nbytes = is.Read(buffer, length);
+	size_t nbytes = is.Read(lock, buffer, length);
 	assert(nbytes > 0 || is.IsEOF());
 
 	return nbytes;
diff --git a/src/decoder/Thread.cxx b/src/decoder/Thread.cxx
index 91a4344d2..d042c7a5c 100644
--- a/src/decoder/Thread.cxx
+++ b/src/decoder/Thread.cxx
@@ -55,7 +55,8 @@ static constexpr Domain decoder_thread_domain("decoder_thread");
 static bool
 decoder_stream_decode(const DecoderPlugin &plugin,
 		      DecoderBridge &bridge,
-		      InputStream &input_stream)
+		      InputStream &input_stream,
+		      std::unique_lock<Mutex> &lock)
 {
 	assert(plugin.stream_decode != nullptr);
 	assert(bridge.stream_tag == nullptr);
@@ -70,7 +71,7 @@ decoder_stream_decode(const DecoderPlugin &plugin,
 
 	/* rewind the stream, so each plugin gets a fresh start */
 	try {
-		input_stream.Rewind();
+		input_stream.Rewind(lock);
 	} catch (...) {
 	}
 
@@ -161,6 +162,7 @@ decoder_check_plugin(const DecoderPlugin &plugin, const InputStream &is,
 
 static bool
 decoder_run_stream_plugin(DecoderBridge &bridge, InputStream &is,
+			  std::unique_lock<Mutex> &lock,
 			  const char *suffix,
 			  const DecoderPlugin &plugin,
 			  bool &tried_r)
@@ -171,11 +173,12 @@ decoder_run_stream_plugin(DecoderBridge &bridge, InputStream &is,
 	bridge.Reset();
 
 	tried_r = true;
-	return decoder_stream_decode(plugin, bridge, is);
+	return decoder_stream_decode(plugin, bridge, is, lock);
 }
 
 static bool
 decoder_run_stream_locked(DecoderBridge &bridge, InputStream &is,
+			  std::unique_lock<Mutex> &lock,
 			  const char *uri, bool &tried_r)
 {
 	UriSuffixBuffer suffix_buffer;
@@ -183,7 +186,8 @@ decoder_run_stream_locked(DecoderBridge &bridge, InputStream &is,
 
 	using namespace std::placeholders;
 	const auto f = std::bind(decoder_run_stream_plugin,
-				 std::ref(bridge), std::ref(is), suffix,
+				 std::ref(bridge), std::ref(is), std::ref(lock),
+				 suffix,
 				 _1, std::ref(tried_r));
 	return decoder_plugins_try(f);
 }
@@ -192,7 +196,8 @@ decoder_run_stream_locked(DecoderBridge &bridge, InputStream &is,
  * Try decoding a stream, using the fallback plugin.
  */
 static bool
-decoder_run_stream_fallback(DecoderBridge &bridge, InputStream &is)
+decoder_run_stream_fallback(DecoderBridge &bridge, InputStream &is,
+			    std::unique_lock<Mutex> &lock)
 {
 	const struct DecoderPlugin *plugin;
 
@@ -202,7 +207,7 @@ decoder_run_stream_fallback(DecoderBridge &bridge, InputStream &is)
 	plugin = decoder_plugin_from_name("mad");
 #endif
 	return plugin != nullptr && plugin->stream_decode != nullptr &&
-		decoder_stream_decode(*plugin, bridge, is);
+		decoder_stream_decode(*plugin, bridge, is, lock);
 }
 
 /**
@@ -249,16 +254,16 @@ decoder_run_stream(DecoderBridge &bridge, const char *uri)
 
 	MaybeLoadReplayGain(bridge, *input_stream);
 
-	const std::lock_guard<Mutex> protect(dc.mutex);
+	std::unique_lock<Mutex> lock(dc.mutex);
 
 	bool tried = false;
 	return dc.command == DecoderCommand::STOP ||
-		decoder_run_stream_locked(bridge, *input_stream, uri,
+		decoder_run_stream_locked(bridge, *input_stream, lock, uri,
 					  tried) ||
 		/* fallback to mp3: this is needed for bastard streams
 		   that don't have a suffix or set the mimeType */
 		(!tried &&
-		 decoder_run_stream_fallback(bridge, *input_stream));
+		 decoder_run_stream_fallback(bridge, *input_stream, lock));
 }
 
 /**
@@ -282,8 +287,9 @@ TryDecoderFile(DecoderBridge &bridge, Path path_fs, const char *suffix,
 		const std::lock_guard<Mutex> protect(dc.mutex);
 		return decoder_file_decode(plugin, bridge, path_fs);
 	} else if (plugin.stream_decode != nullptr) {
-		const std::lock_guard<Mutex> protect(dc.mutex);
-		return decoder_stream_decode(plugin, bridge, input_stream);
+		std::unique_lock<Mutex> lock(dc.mutex);
+		return decoder_stream_decode(plugin, bridge, input_stream,
+					     lock);
 	} else
 		return false;
 }
diff --git a/src/input/AsyncInputStream.cxx b/src/input/AsyncInputStream.cxx
index ce78d166d..3ccd41353 100644
--- a/src/input/AsyncInputStream.cxx
+++ b/src/input/AsyncInputStream.cxx
@@ -95,7 +95,8 @@ AsyncInputStream::IsEOF() noexcept
 }
 
 void
-AsyncInputStream::Seek(offset_type new_offset)
+AsyncInputStream::Seek(std::unique_lock<Mutex> &lock,
+		       offset_type new_offset)
 {
 	assert(IsReady());
 	assert(seek_state == SeekState::NONE);
@@ -136,7 +137,7 @@ AsyncInputStream::Seek(offset_type new_offset)
 	CondInputStreamHandler cond_handler;
 	const ScopeExchangeInputStreamHandler h(*this, &cond_handler);
 	while (seek_state != SeekState::NONE)
-		cond_handler.cond.wait(mutex);
+		cond_handler.cond.wait(lock);
 
 	Check();
 }
@@ -171,7 +172,8 @@ AsyncInputStream::IsAvailable() noexcept
 }
 
 size_t
-AsyncInputStream::Read(void *ptr, size_t read_size)
+AsyncInputStream::Read(std::unique_lock<Mutex> &lock,
+		       void *ptr, size_t read_size)
 {
 	assert(!GetEventLoop().IsInside());
 
@@ -187,7 +189,7 @@ AsyncInputStream::Read(void *ptr, size_t read_size)
 			break;
 
 		const ScopeExchangeInputStreamHandler h(*this, &cond_handler);
-		cond_handler.cond.wait(mutex);
+		cond_handler.cond.wait(lock);
 	}
 
 	const size_t nbytes = std::min(read_size, r.size);
diff --git a/src/input/AsyncInputStream.hxx b/src/input/AsyncInputStream.hxx
index 958f5f690..2577cd9fa 100644
--- a/src/input/AsyncInputStream.hxx
+++ b/src/input/AsyncInputStream.hxx
@@ -83,10 +83,12 @@ public:
 	/* virtual methods from InputStream */
 	void Check() final;
 	bool IsEOF() noexcept final;
-	void Seek(offset_type new_offset) final;
+	void Seek(std::unique_lock<Mutex> &lock,
+		  offset_type new_offset) final;
 	std::unique_ptr<Tag> ReadTag() noexcept final;
 	bool IsAvailable() noexcept final;
-	size_t Read(void *ptr, size_t read_size) final;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t read_size) final;
 
 protected:
 	/**
diff --git a/src/input/BufferedInputStream.cxx b/src/input/BufferedInputStream.cxx
index d28964dbb..69a557a79 100644
--- a/src/input/BufferedInputStream.cxx
+++ b/src/input/BufferedInputStream.cxx
@@ -64,7 +64,8 @@ BufferedInputStream::Check()
 }
 
 void
-BufferedInputStream::Seek(offset_type new_offset)
+BufferedInputStream::Seek(std::unique_lock<Mutex> &lock,
+			  offset_type new_offset)
 {
 	if (new_offset >= size) {
 		offset = size;
@@ -84,7 +85,7 @@ BufferedInputStream::Seek(offset_type new_offset)
 	wake_cond.notify_one();
 
 	while (seek)
-		client_cond.wait(mutex);
+		client_cond.wait(lock);
 
 	if (seek_error)
 		std::rethrow_exception(std::exchange(seek_error, {}));
@@ -105,7 +106,8 @@ BufferedInputStream::IsAvailable() noexcept
 }
 
 size_t
-BufferedInputStream::Read(void *ptr, size_t s)
+BufferedInputStream::Read(std::unique_lock<Mutex> &lock,
+			  void *ptr, size_t s)
 {
 	if (offset >= size)
 		return 0;
@@ -140,7 +142,7 @@ BufferedInputStream::Read(void *ptr, size_t s)
 			wake_cond.notify_one();
 		}
 
-		client_cond.wait(mutex);
+		client_cond.wait(lock);
 	}
 }
 
@@ -156,7 +158,7 @@ BufferedInputStream::RunThread() noexcept
 
 		if (seek) {
 			try {
-				input->Seek(seek_offset);
+				input->Seek(lock, seek_offset);
 			} catch (...) {
 				seek_error = std::current_exception();
 			}
@@ -183,7 +185,7 @@ BufferedInputStream::RunThread() noexcept
 					   offset to prepare filling
 					   the buffer from there */
 					try {
-						input->Seek(offset);
+						input->Seek(lock, offset);
 					} catch (...) {
 						read_error = std::current_exception();
 						client_cond.notify_one();
@@ -195,7 +197,8 @@ BufferedInputStream::RunThread() noexcept
 			}
 
 			try {
-				size_t nbytes = input->Read(w.data, w.size);
+				size_t nbytes = input->Read(lock,
+							    w.data, w.size);
 				buffer.Commit(read_offset,
 					      read_offset + nbytes);
 			} catch (...) {
diff --git a/src/input/BufferedInputStream.hxx b/src/input/BufferedInputStream.hxx
index 46a85a470..dcb6282a1 100644
--- a/src/input/BufferedInputStream.hxx
+++ b/src/input/BufferedInputStream.hxx
@@ -85,12 +85,13 @@ public:
 	/* we don't need to implement Update() because all attributes
 	   have been copied already in our constructor */
 	//void Update() noexcept;
-	void Seek(offset_type offset) override;
+	void Seek(std::unique_lock<Mutex> &lock, offset_type offset) override;
 	bool IsEOF() noexcept override;
 	/* we don't support tags */
 	// std::unique_ptr<Tag> ReadTag() override;
 	bool IsAvailable() noexcept override;
-	size_t Read(void *ptr, size_t size) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
 
 	/* virtual methods from class InputStreamHandler */
 	void OnInputStreamReady() noexcept override {
diff --git a/src/input/FailingInputStream.hxx b/src/input/FailingInputStream.hxx
index 008a1ceae..f150fd972 100644
--- a/src/input/FailingInputStream.hxx
+++ b/src/input/FailingInputStream.hxx
@@ -45,7 +45,7 @@ public:
 		std::rethrow_exception(error);
 	}
 
-	void Seek(offset_type) override {
+	void Seek(std::unique_lock<Mutex> &, offset_type) override {
 		std::rethrow_exception(error);
 	}
 
@@ -53,7 +53,7 @@ public:
 		return false;
 	}
 
-	size_t Read(void *, size_t) override {
+	size_t Read(std::unique_lock<Mutex> &, void *, size_t) override {
 		std::rethrow_exception(error);
 	}
 };
diff --git a/src/input/IcyInputStream.cxx b/src/input/IcyInputStream.cxx
index 4614d8f81..3d85ea47a 100644
--- a/src/input/IcyInputStream.cxx
+++ b/src/input/IcyInputStream.cxx
@@ -80,13 +80,14 @@ IcyInputStream::ReadTag() noexcept
 }
 
 size_t
-IcyInputStream::Read(void *ptr, size_t read_size)
+IcyInputStream::Read(std::unique_lock<Mutex> &lock,
+		     void *ptr, size_t read_size)
 {
 	if (!IsEnabled())
-		return ProxyInputStream::Read(ptr, read_size);
+		return ProxyInputStream::Read(lock, ptr, read_size);
 
 	while (true) {
-		size_t nbytes = ProxyInputStream::Read(ptr, read_size);
+		size_t nbytes = ProxyInputStream::Read(lock, ptr, read_size);
 		if (nbytes == 0)
 			return 0;
 
diff --git a/src/input/IcyInputStream.hxx b/src/input/IcyInputStream.hxx
index 5a6a69074..183cc46d7 100644
--- a/src/input/IcyInputStream.hxx
+++ b/src/input/IcyInputStream.hxx
@@ -66,7 +66,8 @@ public:
 	/* virtual methods from InputStream */
 	void Update() noexcept override;
 	std::unique_ptr<Tag> ReadTag() noexcept override;
-	size_t Read(void *ptr, size_t size) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
 };
 
 #endif
diff --git a/src/input/InputStream.cxx b/src/input/InputStream.cxx
index e125a0409..f808fb5ee 100644
--- a/src/input/InputStream.cxx
+++ b/src/input/InputStream.cxx
@@ -72,7 +72,7 @@ InputStream::CheapSeeking() const noexcept
 }
 
 void
-InputStream::Seek(gcc_unused offset_type new_offset)
+InputStream::Seek(std::unique_lock<Mutex> &, gcc_unused offset_type new_offset)
 {
 	throw std::runtime_error("Seeking is not implemented");
 }
@@ -80,15 +80,15 @@ InputStream::Seek(gcc_unused offset_type new_offset)
 void
 InputStream::LockSeek(offset_type _offset)
 {
-	const std::lock_guard<Mutex> protect(mutex);
-	Seek(_offset);
+	std::unique_lock<Mutex> lock(mutex);
+	Seek(lock, _offset);
 }
 
 void
 InputStream::LockSkip(offset_type _offset)
 {
-	const std::lock_guard<Mutex> protect(mutex);
-	Skip(_offset);
+	std::unique_lock<Mutex> lock(mutex);
+	Skip(lock, _offset);
 }
 
 std::unique_ptr<Tag>
@@ -119,18 +119,18 @@ InputStream::LockRead(void *ptr, size_t _size)
 #endif
 	assert(_size > 0);
 
-	const std::lock_guard<Mutex> protect(mutex);
-	return Read(ptr, _size);
+	std::unique_lock<Mutex> lock(mutex);
+	return Read(lock, ptr, _size);
 }
 
 void
-InputStream::ReadFull(void *_ptr, size_t _size)
+InputStream::ReadFull(std::unique_lock<Mutex> &lock, void *_ptr, size_t _size)
 {
 	uint8_t *ptr = (uint8_t *)_ptr;
 
 	size_t nbytes_total = 0;
 	while (_size > 0) {
-		size_t nbytes = Read(ptr + nbytes_total, _size);
+		size_t nbytes = Read(lock, ptr + nbytes_total, _size);
 		if (nbytes == 0)
 			throw std::runtime_error("Unexpected end of file");
 
@@ -148,8 +148,8 @@ InputStream::LockReadFull(void *ptr, size_t _size)
 #endif
 	assert(_size > 0);
 
-	const std::lock_guard<Mutex> protect(mutex);
-	ReadFull(ptr, _size);
+	std::unique_lock<Mutex> lock(mutex);
+	ReadFull(lock, ptr, _size);
 }
 
 bool
diff --git a/src/input/InputStream.hxx b/src/input/InputStream.hxx
index ba8156d6e..7b19a1e0b 100644
--- a/src/input/InputStream.hxx
+++ b/src/input/InputStream.hxx
@@ -271,9 +271,11 @@ public:
 	 *
 	 * Throws std::runtime_error on error.
 	 *
+	 * @param lock the locked mutex; may be used to wait on
+	 * condition variables
 	 * @param offset the relative offset
 	 */
-	virtual void Seek(offset_type offset);
+	virtual void Seek(std::unique_lock<Mutex> &lock, offset_type offset);
 
 	/**
 	 * Wrapper for Seek() which locks and unlocks the mutex; the
@@ -285,8 +287,8 @@ public:
 	 * Rewind to the beginning of the stream.  This is a wrapper
 	 * for Seek(0, error).
 	 */
-	void Rewind() {
-		Seek(0);
+	void Rewind(std::unique_lock<Mutex> &lock) {
+		Seek(lock, 0);
 	}
 
 	void LockRewind() {
@@ -296,8 +298,9 @@ public:
 	/**
 	 * Skip input bytes.
 	 */
-	void Skip(offset_type _offset) {
-		Seek(GetOffset() + _offset);
+	void Skip(std::unique_lock<Mutex> &lock,
+		  offset_type _offset) {
+		Seek(lock, GetOffset() + _offset);
 	}
 
 	void LockSkip(offset_type _offset);
@@ -351,12 +354,15 @@ public:
 	 *
 	 * Throws std::runtime_error on error.
 	 *
+	 * @param lock the locked mutex; may be used to wait on
+	 * condition variables
 	 * @param ptr the buffer to read into
 	 * @param size the maximum number of bytes to read
 	 * @return the number of bytes read
 	 */
 	gcc_nonnull_all
-	virtual size_t Read(void *ptr, size_t size) = 0;
+	virtual size_t Read(std::unique_lock<Mutex> &lock,
+			    void *ptr, size_t size) = 0;
 
 	/**
 	 * Wrapper for Read() which locks and unlocks the mutex;
@@ -379,7 +385,7 @@ public:
 	 * @return true if the whole data was read, false otherwise.
 	 */
 	gcc_nonnull_all
-	void ReadFull(void *ptr, size_t size);
+	void ReadFull(std::unique_lock<Mutex> &lock, void *ptr, size_t size);
 
 	/**
 	 * Wrapper for ReadFull() which locks and unlocks the mutex;
diff --git a/src/input/ProxyInputStream.cxx b/src/input/ProxyInputStream.cxx
index f05f439f7..345e6f319 100644
--- a/src/input/ProxyInputStream.cxx
+++ b/src/input/ProxyInputStream.cxx
@@ -89,12 +89,13 @@ ProxyInputStream::Update() noexcept
 }
 
 void
-ProxyInputStream::Seek(offset_type new_offset)
+ProxyInputStream::Seek(std::unique_lock<Mutex> &lock,
+		       offset_type new_offset)
 {
 	while (!input)
-		set_input_cond.wait(mutex);
+		set_input_cond.wait(lock);
 
-	input->Seek(new_offset);
+	input->Seek(lock, new_offset);
 	CopyAttributes();
 }
 
@@ -120,12 +121,13 @@ ProxyInputStream::IsAvailable() noexcept
 }
 
 size_t
-ProxyInputStream::Read(void *ptr, size_t read_size)
+ProxyInputStream::Read(std::unique_lock<Mutex> &lock,
+		       void *ptr, size_t read_size)
 {
 	while (!input)
-		set_input_cond.wait(mutex);
+		set_input_cond.wait(lock);
 
-	size_t nbytes = input->Read(ptr, read_size);
+	size_t nbytes = input->Read(lock, ptr, read_size);
 	CopyAttributes();
 	return nbytes;
 }
diff --git a/src/input/ProxyInputStream.hxx b/src/input/ProxyInputStream.hxx
index 853deb11c..d030e16ed 100644
--- a/src/input/ProxyInputStream.hxx
+++ b/src/input/ProxyInputStream.hxx
@@ -60,11 +60,13 @@ public:
 	/* virtual methods from InputStream */
 	void Check() override;
 	void Update() noexcept override;
-	void Seek(offset_type new_offset) override;
+	void Seek(std::unique_lock<Mutex> &lock,
+		  offset_type new_offset) override;
 	bool IsEOF() noexcept override;
 	std::unique_ptr<Tag> ReadTag() noexcept override;
 	bool IsAvailable() noexcept override;
-	size_t Read(void *ptr, size_t read_size) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t read_size) override;
 
 protected:
 	/**
diff --git a/src/input/RewindInputStream.cxx b/src/input/RewindInputStream.cxx
index 98f2d1967..cb760adb1 100644
--- a/src/input/RewindInputStream.cxx
+++ b/src/input/RewindInputStream.cxx
@@ -60,8 +60,9 @@ public:
 		return !ReadingFromBuffer() && ProxyInputStream::IsEOF();
 	}
 
-	size_t Read(void *ptr, size_t size) override;
-	void Seek(offset_type offset) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
+	void Seek(std::unique_lock<Mutex> &lock, offset_type offset) override;
 
 private:
 	/**
@@ -74,7 +75,8 @@ private:
 };
 
 size_t
-RewindInputStream::Read(void *ptr, size_t read_size)
+RewindInputStream::Read(std::unique_lock<Mutex> &lock,
+			void *ptr, size_t read_size)
 {
 	if (ReadingFromBuffer()) {
 		/* buffered read */
@@ -93,7 +95,7 @@ RewindInputStream::Read(void *ptr, size_t read_size)
 	} else {
 		/* pass method call to underlying stream */
 
-		size_t nbytes = input->Read(ptr, read_size);
+		size_t nbytes = input->Read(lock, ptr, read_size);
 
 		if (input->GetOffset() > (offset_type)sizeof(buffer))
 			/* disable buffering */
@@ -114,7 +116,7 @@ RewindInputStream::Read(void *ptr, size_t read_size)
 }
 
 void
-RewindInputStream::Seek(offset_type new_offset)
+RewindInputStream::Seek(std::unique_lock<Mutex> &lock, offset_type new_offset)
 {
 	assert(IsReady());
 
@@ -132,7 +134,7 @@ RewindInputStream::Seek(offset_type new_offset)
 		   buffered range now */
 		tail = 0;
 
-		ProxyInputStream::Seek(new_offset);
+		ProxyInputStream::Seek(lock, new_offset);
 	}
 }
 
diff --git a/src/input/ThreadInputStream.cxx b/src/input/ThreadInputStream.cxx
index 5a21022e1..e1be3ecdc 100644
--- a/src/input/ThreadInputStream.cxx
+++ b/src/input/ThreadInputStream.cxx
@@ -130,7 +130,8 @@ ThreadInputStream::IsAvailable() noexcept
 }
 
 inline size_t
-ThreadInputStream::Read(void *ptr, size_t read_size)
+ThreadInputStream::Read(std::unique_lock<Mutex> &lock,
+			void *ptr, size_t read_size)
 {
 	assert(!thread.IsInside());
 
@@ -154,7 +155,7 @@ ThreadInputStream::Read(void *ptr, size_t read_size)
 			return 0;
 
 		const ScopeExchangeInputStreamHandler h(*this, &cond_handler);
-		cond_handler.cond.wait(mutex);
+		cond_handler.cond.wait(lock);
 	}
 }
 
diff --git a/src/input/ThreadInputStream.hxx b/src/input/ThreadInputStream.hxx
index 14b849238..3c946e12a 100644
--- a/src/input/ThreadInputStream.hxx
+++ b/src/input/ThreadInputStream.hxx
@@ -94,7 +94,8 @@ public:
 	void Check() override final;
 	bool IsEOF() noexcept final;
 	bool IsAvailable() noexcept final;
-	size_t Read(void *ptr, size_t size) override final;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override final;
 
 protected:
 	/**
diff --git a/src/input/plugins/CdioParanoiaInputPlugin.cxx b/src/input/plugins/CdioParanoiaInputPlugin.cxx
index 0079e55a9..9178f8a4a 100644
--- a/src/input/plugins/CdioParanoiaInputPlugin.cxx
+++ b/src/input/plugins/CdioParanoiaInputPlugin.cxx
@@ -91,8 +91,9 @@ class CdioParanoiaInputStream final : public InputStream {
 
 	/* virtual methods from InputStream */
 	bool IsEOF() noexcept override;
-	size_t Read(void *ptr, size_t size) override;
-	void Seek(offset_type offset) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
+	void Seek(std::unique_lock<Mutex> &lock, offset_type offset) override;
 };
 
 static constexpr Domain cdio_domain("cdio");
@@ -255,7 +256,8 @@ input_cdio_open(const char *uri,
 }
 
 void
-CdioParanoiaInputStream::Seek(offset_type new_offset)
+CdioParanoiaInputStream::Seek(std::unique_lock<Mutex> &,
+			      offset_type new_offset)
 {
 	if (new_offset > size)
 		throw FormatRuntimeError("Invalid offset to seek %ld (%ld)",
@@ -276,7 +278,8 @@ CdioParanoiaInputStream::Seek(offset_type new_offset)
 }
 
 size_t
-CdioParanoiaInputStream::Read(void *ptr, size_t length)
+CdioParanoiaInputStream::Read(std::unique_lock<Mutex> &,
+			      void *ptr, size_t length)
 {
 	size_t nbytes = 0;
 	char *wptr = (char *) ptr;
diff --git a/src/input/plugins/FfmpegInputPlugin.cxx b/src/input/plugins/FfmpegInputPlugin.cxx
index 198f4bd17..febc44872 100644
--- a/src/input/plugins/FfmpegInputPlugin.cxx
+++ b/src/input/plugins/FfmpegInputPlugin.cxx
@@ -49,8 +49,10 @@ public:
 
 	/* virtual methods from InputStream */
 	bool IsEOF() noexcept override;
-	size_t Read(void *ptr, size_t size) override;
-	void Seek(offset_type offset) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
+	void Seek(std::unique_lock<Mutex> &lock,
+		  offset_type offset) override;
 };
 
 gcc_const
@@ -79,7 +81,8 @@ input_ffmpeg_open(const char *uri,
 }
 
 size_t
-FfmpegInputStream::Read(void *ptr, size_t read_size)
+FfmpegInputStream::Read(std::unique_lock<Mutex> &,
+			void *ptr, size_t read_size)
 {
 	size_t result;
 
@@ -99,7 +102,7 @@ FfmpegInputStream::IsEOF() noexcept
 }
 
 void
-FfmpegInputStream::Seek(offset_type new_offset)
+FfmpegInputStream::Seek(std::unique_lock<Mutex> &, offset_type new_offset)
 {
 	uint64_t result;
 
diff --git a/src/input/plugins/FileInputPlugin.cxx b/src/input/plugins/FileInputPlugin.cxx
index 989d3de74..a61c94c2b 100644
--- a/src/input/plugins/FileInputPlugin.cxx
+++ b/src/input/plugins/FileInputPlugin.cxx
@@ -48,8 +48,10 @@ public:
 		return GetOffset() >= GetSize();
 	}
 
-	size_t Read(void *ptr, size_t size) override;
-	void Seek(offset_type offset) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
+	void Seek(std::unique_lock<Mutex> &lock,
+		  offset_type offset) override;
 };
 
 InputStreamPtr
@@ -74,7 +76,8 @@ OpenFileInputStream(Path path, Mutex &mutex)
 }
 
 void
-FileInputStream::Seek(offset_type new_offset)
+FileInputStream::Seek(std::unique_lock<Mutex> &,
+		      offset_type new_offset)
 {
 	{
 		const ScopeUnlock unlock(mutex);
@@ -85,7 +88,8 @@ FileInputStream::Seek(offset_type new_offset)
 }
 
 size_t
-FileInputStream::Read(void *ptr, size_t read_size)
+FileInputStream::Read(std::unique_lock<Mutex> &,
+		      void *ptr, size_t read_size)
 {
 	size_t nbytes;
 
diff --git a/src/input/plugins/SmbclientInputPlugin.cxx b/src/input/plugins/SmbclientInputPlugin.cxx
index dfd95103d..361d0e18e 100644
--- a/src/input/plugins/SmbclientInputPlugin.cxx
+++ b/src/input/plugins/SmbclientInputPlugin.cxx
@@ -56,8 +56,9 @@ public:
 		return offset >= size;
 	}
 
-	size_t Read(void *ptr, size_t size) override;
-	void Seek(offset_type offset) override;
+	size_t Read(std::unique_lock<Mutex> &lock,
+		    void *ptr, size_t size) override;
+	void Seek(std::unique_lock<Mutex> &lock, offset_type offset) override;
 };
 
 /*
@@ -118,7 +119,8 @@ input_smbclient_open(const char *uri,
 }
 
 size_t
-SmbclientInputStream::Read(void *ptr, size_t read_size)
+SmbclientInputStream::Read(std::unique_lock<Mutex> &,
+			   void *ptr, size_t read_size)
 {
 	ssize_t nbytes;
 
@@ -136,7 +138,8 @@ SmbclientInputStream::Read(void *ptr, size_t read_size)
 }
 
 void
-SmbclientInputStream::Seek(offset_type new_offset)
+SmbclientInputStream::Seek(std::unique_lock<Mutex> &,
+			   offset_type new_offset)
 {
 	off_t result;
 
diff --git a/src/tag/Aiff.cxx b/src/tag/Aiff.cxx
index 3cc3a7f43..77bf06701 100644
--- a/src/tag/Aiff.cxx
+++ b/src/tag/Aiff.cxx
@@ -39,14 +39,14 @@ struct aiff_chunk_header {
 };
 
 size_t
-aiff_seek_id3(InputStream &is)
+aiff_seek_id3(InputStream &is, std::unique_lock<Mutex> &lock)
 {
 	/* seek to the beginning and read the AIFF header */
 
-	is.Rewind();
+	is.Rewind(lock);
 
 	aiff_header header;
-	is.ReadFull(&header, sizeof(header));
+	is.ReadFull(lock, &header, sizeof(header));
 	if (memcmp(header.id, "FORM", 4) != 0 ||
 	    (is.KnownSize() && FromBE32(header.size) > is.GetSize()) ||
 	    (memcmp(header.format, "AIFF", 4) != 0 &&
@@ -57,7 +57,7 @@ aiff_seek_id3(InputStream &is)
 		/* read the chunk header */
 
 		aiff_chunk_header chunk;
-		is.ReadFull(&chunk, sizeof(chunk));
+		is.ReadFull(lock, &chunk, sizeof(chunk));
 
 		size_t size = FromBE32(chunk.size);
 		if (size > size_t(std::numeric_limits<int>::max()))
@@ -73,6 +73,6 @@ aiff_seek_id3(InputStream &is)
 			/* pad byte */
 			++size;
 
-		is.Skip(size);
+		is.Skip(lock, size);
 	}
 }
diff --git a/src/tag/Aiff.hxx b/src/tag/Aiff.hxx
index 28d20c86c..eb59afe71 100644
--- a/src/tag/Aiff.hxx
+++ b/src/tag/Aiff.hxx
@@ -25,9 +25,12 @@
 #ifndef MPD_AIFF_HXX
 #define MPD_AIFF_HXX
 
+#include <mutex>
+
 #include <stddef.h>
 
 class InputStream;
+class Mutex;
 
 /**
  * Seeks the AIFF file to the ID3 chunk.
@@ -38,6 +41,6 @@ class InputStream;
  * @return the size of the ID3 chunk
  */
 size_t
-aiff_seek_id3(InputStream &is);
+aiff_seek_id3(InputStream &is, std::unique_lock<Mutex> &lock);
 
 #endif
diff --git a/src/tag/ApeLoader.cxx b/src/tag/ApeLoader.cxx
index eb2c76b75..15a124824 100644
--- a/src/tag/ApeLoader.cxx
+++ b/src/tag/ApeLoader.cxx
@@ -40,15 +40,15 @@ struct ApeFooter {
 bool
 tag_ape_scan(InputStream &is, ApeTagCallback callback)
 try {
-	const std::lock_guard<Mutex> protect(is.mutex);
+	std::unique_lock<Mutex> lock(is.mutex);
 
 	if (!is.KnownSize() || !is.CheapSeeking())
 		return false;
 
 	/* determine if file has an apeV2 tag */
 	ApeFooter footer;
-	is.Seek(is.GetSize() - sizeof(footer));
-	is.ReadFull(&footer, sizeof(footer));
+	is.Seek(lock, is.GetSize() - sizeof(footer));
+	is.ReadFull(lock, &footer, sizeof(footer));
 
 	if (memcmp(footer.id, "APETAGEX", sizeof(footer.id)) != 0 ||
 	    FromLE32(footer.version) != 2000)
@@ -61,14 +61,14 @@ try {
 	    remaining > 1024 * 1024)
 		return false;
 
-	is.Seek(is.GetSize() - remaining);
+	is.Seek(lock, is.GetSize() - remaining);
 
 	/* read tag into buffer */
 	remaining -= sizeof(footer);
 	assert(remaining > 10);
 
 	std::unique_ptr<char[]> buffer(new char[remaining]);
-	is.ReadFull(buffer.get(), remaining);
+	is.ReadFull(lock, buffer.get(), remaining);
 
 	/* read tags */
 	unsigned n = FromLE32(footer.count);
diff --git a/src/tag/Id3Load.cxx b/src/tag/Id3Load.cxx
index fe9db5c48..7494a8ac1 100644
--- a/src/tag/Id3Load.cxx
+++ b/src/tag/Id3Load.cxx
@@ -37,11 +37,12 @@ tag_is_id3v1(struct id3_tag *tag) noexcept
 }
 
 static long
-get_id3v2_footer_size(InputStream &is, offset_type offset)
+get_id3v2_footer_size(InputStream &is, std::unique_lock<Mutex> &lock,
+		      offset_type offset)
 try {
 	id3_byte_t buf[ID3_TAG_QUERYSIZE];
-	is.Seek(offset);
-	is.ReadFull(buf, sizeof(buf));
+	is.Seek(lock, offset);
+	is.ReadFull(lock, buf, sizeof(buf));
 
 	return id3_tag_query(buf, sizeof(buf));
 } catch (...) {
@@ -49,10 +50,10 @@ try {
 }
 
 static UniqueId3Tag
-ReadId3Tag(InputStream &is)
+ReadId3Tag(InputStream &is, std::unique_lock<Mutex> &lock)
 try {
 	id3_byte_t query_buffer[ID3_TAG_QUERYSIZE];
-	is.ReadFull(query_buffer, sizeof(query_buffer));
+	is.ReadFull(lock, query_buffer, sizeof(query_buffer));
 
 	/* Look for a tag header */
 	long tag_size = id3_tag_query(query_buffer, sizeof(query_buffer));
@@ -72,7 +73,7 @@ try {
 
 	/* now read the remaining bytes */
 	const size_t remaining = tag_size - sizeof(query_buffer);
-	is.ReadFull(end, remaining);
+	is.ReadFull(lock, end, remaining);
 
 	return UniqueId3Tag(id3_tag_parse(tag_buffer.get(), tag_size));
 } catch (...) {
@@ -80,20 +81,20 @@ try {
 }
 
 static UniqueId3Tag
-ReadId3Tag(InputStream &is, offset_type offset)
+ReadId3Tag(InputStream &is, std::unique_lock<Mutex> &lock, offset_type offset)
 try {
-	is.Seek(offset);
+	is.Seek(lock, offset);
 
-	return ReadId3Tag(is);
+	return ReadId3Tag(is, lock);
 } catch (...) {
 	return nullptr;
 }
 
 static UniqueId3Tag
-ReadId3v1Tag(InputStream &is)
+ReadId3v1Tag(InputStream &is, std::unique_lock<Mutex> &lock)
 try {
 	id3_byte_t buffer[ID3V1_SIZE];
-	is.ReadFull(buffer, ID3V1_SIZE);
+	is.ReadFull(lock, buffer, ID3V1_SIZE);
 
 	return UniqueId3Tag(id3_tag_parse(buffer, ID3V1_SIZE));
 } catch (...) {
@@ -101,18 +102,19 @@ try {
 }
 
 static UniqueId3Tag
-ReadId3v1Tag(InputStream &is, offset_type offset)
+ReadId3v1Tag(InputStream &is, std::unique_lock<Mutex> &lock,
+	     offset_type offset)
 try {
-	is.Seek(offset);
-	return ReadId3v1Tag(is);
+	is.Seek(lock, offset);
+	return ReadId3v1Tag(is, lock);
 } catch (...) {
 	return nullptr;
 }
 
 static UniqueId3Tag
-tag_id3_find_from_beginning(InputStream &is)
+tag_id3_find_from_beginning(InputStream &is, std::unique_lock<Mutex> &lock)
 try {
-	auto tag = ReadId3Tag(is);
+	auto tag = ReadId3Tag(is, lock);
 	if (!tag) {
 		return nullptr;
 	} else if (tag_is_id3v1(tag.get())) {
@@ -129,7 +131,7 @@ try {
 			break;
 
 		/* Get the tag specified by the SEEK frame */
-		auto seektag = ReadId3Tag(is, is.GetOffset() + seek);
+		auto seektag = ReadId3Tag(is, lock, is.GetOffset() + seek);
 		if (!seektag || tag_is_id3v1(seektag.get()))
 			break;
 
@@ -143,7 +145,7 @@ try {
 }
 
 static UniqueId3Tag
-tag_id3_find_from_end(InputStream &is)
+tag_id3_find_from_end(InputStream &is, std::unique_lock<Mutex> &lock)
 try {
 	if (!is.KnownSize() || !is.CheapSeeking())
 		return nullptr;
@@ -155,7 +157,7 @@ try {
 	offset_type offset = size - ID3V1_SIZE;
 
 	/* Get an id3v1 tag from the end of file for later use */
-	auto v1tag = ReadId3v1Tag(is, offset);
+	auto v1tag = ReadId3v1Tag(is, lock, offset);
 	if (!v1tag)
 		offset = size;
 
@@ -164,7 +166,7 @@ try {
 		return v1tag;
 
 	long tag_offset =
-		get_id3v2_footer_size(is, offset - ID3_TAG_QUERYSIZE);
+		get_id3v2_footer_size(is, lock, offset - ID3_TAG_QUERYSIZE);
 	if (tag_offset >= 0)
 		return v1tag;
 
@@ -173,7 +175,7 @@ try {
 		return v1tag;
 
 	/* Get the tag which the footer belongs to */
-	auto tag = ReadId3Tag(is, offset - tag_size);
+	auto tag = ReadId3Tag(is, lock, offset - tag_size);
 	if (!tag)
 		return v1tag;
 
@@ -184,13 +186,13 @@ try {
 }
 
 static UniqueId3Tag
-tag_id3_riff_aiff_load(InputStream &is)
+tag_id3_riff_aiff_load(InputStream &is, std::unique_lock<Mutex> &lock)
 try {
 	size_t size;
 	try {
-		size = riff_seek_id3(is);
+		size = riff_seek_id3(is, lock);
 	} catch (...) {
-		size = aiff_seek_id3(is);
+		size = aiff_seek_id3(is, lock);
 	}
 
 	if (size > 4 * 1024 * 1024)
@@ -198,7 +200,7 @@ try {
 		return nullptr;
 
 	std::unique_ptr<id3_byte_t[]> buffer(new id3_byte_t[size]);
-	is.ReadFull(buffer.get(), size);
+	is.ReadFull(lock, buffer.get(), size);
 
 	return UniqueId3Tag(id3_tag_parse(buffer.get(), size));
 } catch (...) {
@@ -208,13 +210,13 @@ try {
 UniqueId3Tag
 tag_id3_load(InputStream &is)
 try {
-	const std::lock_guard<Mutex> protect(is.mutex);
+	std::unique_lock<Mutex> lock(is.mutex);
 
-	auto tag = tag_id3_find_from_beginning(is);
+	auto tag = tag_id3_find_from_beginning(is, lock);
 	if (tag == nullptr && is.CheapSeeking()) {
-		tag = tag_id3_riff_aiff_load(is);
+		tag = tag_id3_riff_aiff_load(is, lock);
 		if (tag == nullptr)
-			tag = tag_id3_find_from_end(is);
+			tag = tag_id3_find_from_end(is, lock);
 	}
 
 	return tag;
diff --git a/src/tag/Riff.cxx b/src/tag/Riff.cxx
index 9671861fe..df4570fd0 100644
--- a/src/tag/Riff.cxx
+++ b/src/tag/Riff.cxx
@@ -39,14 +39,14 @@ struct riff_chunk_header {
 };
 
 size_t
-riff_seek_id3(InputStream &is)
+riff_seek_id3(InputStream &is, std::unique_lock<Mutex> &lock)
 {
 	/* seek to the beginning and read the RIFF header */
 
-	is.Rewind();
+	is.Rewind(lock);
 
 	riff_header header;
-	is.ReadFull(&header, sizeof(header));
+	is.ReadFull(lock, &header, sizeof(header));
 	if (memcmp(header.id, "RIFF", 4) != 0 ||
 	    (is.KnownSize() && FromLE32(header.size) > is.GetSize()))
 		throw std::runtime_error("Not a RIFF file");
@@ -55,7 +55,7 @@ riff_seek_id3(InputStream &is)
 		/* read the chunk header */
 
 		riff_chunk_header chunk;
-		is.ReadFull(&chunk, sizeof(chunk));
+		is.ReadFull(lock, &chunk, sizeof(chunk));
 
 		size_t size = FromLE32(chunk.size);
 		if (size > size_t(std::numeric_limits<int>::max()))
@@ -72,6 +72,6 @@ riff_seek_id3(InputStream &is)
 			/* pad byte */
 			++size;
 
-		is.Skip(size);
+		is.Skip(lock, size);
 	}
 }
diff --git a/src/tag/Riff.hxx b/src/tag/Riff.hxx
index b02cd8197..4a1aac45d 100644
--- a/src/tag/Riff.hxx
+++ b/src/tag/Riff.hxx
@@ -25,8 +25,11 @@
 #ifndef MPD_RIFF_HXX
 #define MPD_RIFF_HXX
 
+#include <mutex>
+
 #include <stddef.h>
 
+class Mutex;
 class InputStream;
 
 /**
@@ -38,6 +41,6 @@ class InputStream;
  * @return the size of the ID3 chunk
  */
 size_t
-riff_seek_id3(InputStream &is);
+riff_seek_id3(InputStream &is, std::unique_lock<Mutex> &lock);
 
 #endif
diff --git a/test/TestRewindInputStream.cxx b/test/TestRewindInputStream.cxx
index 051d5a9ea..3487edcd7 100644
--- a/test/TestRewindInputStream.cxx
+++ b/test/TestRewindInputStream.cxx
@@ -28,7 +28,8 @@ public:
 		return remaining == 0;
 	}
 
-	size_t Read(void *ptr, size_t read_size) override {
+	size_t Read(std::unique_lock<Mutex> &,
+		    void *ptr, size_t read_size) override {
 		size_t nbytes = std::min(remaining, read_size);
 		memcpy(ptr, data, nbytes);
 		data += nbytes;
@@ -51,7 +52,7 @@ TEST(RewindInputStream, Basic)
 	EXPECT_TRUE(ris.get() != sis);
 	EXPECT_TRUE(ris != nullptr);
 
-	const std::lock_guard<Mutex> protect(mutex);
+	std::unique_lock<Mutex> lock(mutex);
 
 	ris->Update();
 	EXPECT_TRUE(ris->IsReady());
@@ -59,50 +60,50 @@ TEST(RewindInputStream, Basic)
 	EXPECT_EQ(offset_type(0), ris->GetOffset());
 
 	char buffer[16];
-	size_t nbytes = ris->Read(buffer, 2);
+	size_t nbytes = ris->Read(lock, buffer, 2);
 	EXPECT_EQ(size_t(2), nbytes);
 	EXPECT_EQ('f', buffer[0]);
 	EXPECT_EQ('o', buffer[1]);
 	EXPECT_EQ(offset_type(2), ris->GetOffset());
 	EXPECT_FALSE(ris->IsEOF());
 
-	nbytes = ris->Read(buffer, 2);
+	nbytes = ris->Read(lock, buffer, 2);
 	EXPECT_EQ(size_t(2), nbytes);
 	EXPECT_EQ('o', buffer[0]);
 	EXPECT_EQ(' ', buffer[1]);
 	EXPECT_EQ(offset_type(4), ris->GetOffset());
 	EXPECT_FALSE(ris->IsEOF());
 
-	ris->Seek(1);
+	ris->Seek(lock, 1);
 	EXPECT_EQ(offset_type(1), ris->GetOffset());
 	EXPECT_FALSE(ris->IsEOF());
 
-	nbytes = ris->Read(buffer, 2);
+	nbytes = ris->Read(lock, buffer, 2);
 	EXPECT_EQ(size_t(2), nbytes);
 	EXPECT_EQ('o', buffer[0]);
 	EXPECT_EQ('o', buffer[1]);
 	EXPECT_EQ(offset_type(3), ris->GetOffset());
 	EXPECT_FALSE(ris->IsEOF());
 
-	ris->Seek(0);
+	ris->Seek(lock, 0);
 	EXPECT_EQ(offset_type(0), ris->GetOffset());
 	EXPECT_FALSE(ris->IsEOF());
 
-	nbytes = ris->Read(buffer, 2);
+	nbytes = ris->Read(lock, buffer, 2);
 	EXPECT_EQ(size_t(2), nbytes);
 	EXPECT_EQ('f', buffer[0]);
 	EXPECT_EQ('o', buffer[1]);
 	EXPECT_EQ(offset_type(2), ris->GetOffset());
 	EXPECT_FALSE(ris->IsEOF());
 
-	nbytes = ris->Read(buffer, sizeof(buffer));
+	nbytes = ris->Read(lock, buffer, sizeof(buffer));
 	EXPECT_EQ(size_t(2), nbytes);
 	EXPECT_EQ('o', buffer[0]);
 	EXPECT_EQ(' ', buffer[1]);
 	EXPECT_EQ(offset_type(4), ris->GetOffset());
 	EXPECT_FALSE(ris->IsEOF());
 
-	nbytes = ris->Read(buffer, sizeof(buffer));
+	nbytes = ris->Read(lock, buffer, sizeof(buffer));
 	EXPECT_EQ(size_t(3), nbytes);
 	EXPECT_EQ('b', buffer[0]);
 	EXPECT_EQ('a', buffer[1]);
@@ -110,11 +111,11 @@ TEST(RewindInputStream, Basic)
 	EXPECT_EQ(offset_type(7), ris->GetOffset());
 	EXPECT_TRUE(ris->IsEOF());
 
-	ris->Seek(3);
+	ris->Seek(lock, 3);
 	EXPECT_EQ(offset_type(3), ris->GetOffset());
 	EXPECT_FALSE(ris->IsEOF());
 
-	nbytes = ris->Read(buffer, sizeof(buffer));
+	nbytes = ris->Read(lock, buffer, sizeof(buffer));
 	EXPECT_EQ(size_t(4), nbytes);
 	EXPECT_EQ(' ', buffer[0]);
 	EXPECT_EQ('b', buffer[1]);
diff --git a/test/run_input.cxx b/test/run_input.cxx
index 7a5b88e3f..3b47daf4d 100644
--- a/test/run_input.cxx
+++ b/test/run_input.cxx
@@ -131,7 +131,7 @@ tag_save(FILE *file, const Tag &tag)
 static int
 dump_input_stream(InputStream *is)
 {
-	const std::lock_guard<Mutex> protect(is->mutex);
+	std::unique_lock<Mutex> lock(is->mutex);
 
 	/* print meta data */
 
@@ -150,7 +150,7 @@ dump_input_stream(InputStream *is)
 		}
 
 		char buffer[4096];
-		size_t num_read = is->Read(buffer, sizeof(buffer));
+		size_t num_read = is->Read(lock, buffer, sizeof(buffer));
 		if (num_read == 0)
 			break;