diff --git a/src/input/plugins/CurlInputPlugin.cxx b/src/input/plugins/CurlInputPlugin.cxx
index bb264381d..c6a62d286 100644
--- a/src/input/plugins/CurlInputPlugin.cxx
+++ b/src/input/plugins/CurlInputPlugin.cxx
@@ -270,6 +270,7 @@ CurlInputStream::OnData(ConstBuffer<void> data)
 void
 CurlInputStream::OnEnd()
 {
+	const std::lock_guard<Mutex> protect(mutex);
 	cond.broadcast();
 
 	AsyncInputStream::SetClosed();
@@ -278,6 +279,7 @@ CurlInputStream::OnEnd()
 void
 CurlInputStream::OnError(std::exception_ptr e) noexcept
 {
+	const std::lock_guard<Mutex> protect(mutex);
 	postponed_exception = std::move(e);
 
 	if (IsSeekPending())
diff --git a/src/pcm/SampleFormat.hxx b/src/pcm/SampleFormat.hxx
index badfe1781..408357825 100644
--- a/src/pcm/SampleFormat.hxx
+++ b/src/pcm/SampleFormat.hxx
@@ -122,7 +122,7 @@ sample_format_size(SampleFormat format)
  * @param format a #SampleFormat enum value
  * @return the string
  */
-gcc_pure gcc_malloc gcc_returns_nonnull
+gcc_pure gcc_returns_nonnull
 const char *
 sample_format_to_string(SampleFormat format) noexcept;