diff --git a/src/decoder/plugins/FlacDecoderPlugin.cxx b/src/decoder/plugins/FlacDecoderPlugin.cxx
index 5fa8a0ae3..04364ad6a 100644
--- a/src/decoder/plugins/FlacDecoderPlugin.cxx
+++ b/src/decoder/plugins/FlacDecoderPlugin.cxx
@@ -24,6 +24,7 @@
 #include "FlacCommon.hxx"
 #include "lib/xiph/FlacMetadataChain.hxx"
 #include "OggCodec.hxx"
+#include "input/InputStream.hxx"
 #include "fs/Path.hxx"
 #include "fs/NarrowPath.hxx"
 #include "Log.hxx"
diff --git a/src/lib/xiph/FlacMetadataChain.cxx b/src/lib/xiph/FlacMetadataChain.cxx
index b41ac9d68..379f3e74f 100644
--- a/src/lib/xiph/FlacMetadataChain.cxx
+++ b/src/lib/xiph/FlacMetadataChain.cxx
@@ -20,8 +20,21 @@
 #include "config.h"
 #include "FlacMetadataChain.hxx"
 #include "FlacMetadataIterator.hxx"
+#include "FlacIOHandle.hxx"
 #include "decoder/plugins/FlacMetadata.hxx"
 
+bool
+FlacMetadataChain::Read(InputStream &is) noexcept
+{
+	return Read(::ToFlacIOHandle(is), ::GetFlacIOCallbacks(is));
+}
+
+bool
+FlacMetadataChain::ReadOgg(InputStream &is) noexcept
+{
+	return ReadOgg(::ToFlacIOHandle(is), ::GetFlacIOCallbacks(is));
+}
+
 void
 FlacMetadataChain::Scan(TagHandler &handler) noexcept
 {
diff --git a/src/lib/xiph/FlacMetadataChain.hxx b/src/lib/xiph/FlacMetadataChain.hxx
index 3d5070e2a..bc62c4ca2 100644
--- a/src/lib/xiph/FlacMetadataChain.hxx
+++ b/src/lib/xiph/FlacMetadataChain.hxx
@@ -20,11 +20,11 @@
 #ifndef MPD_FLAC_METADATA_CHAIN_HXX
 #define MPD_FLAC_METADATA_CHAIN_HXX
 
-#include "FlacIOHandle.hxx"
 #include "Compiler.h"
 
 #include <FLAC/metadata.h>
 
+class InputStream;
 class TagHandler;
 
 class FlacMetadataChain {
@@ -52,9 +52,7 @@ public:
 								  callbacks);
 	}
 
-	bool Read(InputStream &is) noexcept {
-		return Read(::ToFlacIOHandle(is), ::GetFlacIOCallbacks(is));
-	}
+	bool Read(InputStream &is) noexcept;
 
 	bool ReadOgg(const char *path) noexcept {
 		return ::FLAC__metadata_chain_read_ogg(chain, path);
@@ -67,9 +65,7 @@ public:
 								      callbacks);
 	}
 
-	bool ReadOgg(InputStream &is) {
-		return ReadOgg(::ToFlacIOHandle(is), ::GetFlacIOCallbacks(is));
-	}
+	bool ReadOgg(InputStream &is) noexcept;
 
 	gcc_pure
 	FLAC__Metadata_ChainStatus GetStatus() const noexcept {