diff --git a/src/decoder/DecoderBuffer.cxx b/src/decoder/DecoderBuffer.cxx
index 258edfab8..9eb468b67 100644
--- a/src/decoder/DecoderBuffer.cxx
+++ b/src/decoder/DecoderBuffer.cxx
@@ -75,12 +75,6 @@ decoder_buffer_get_stream(const DecoderBuffer *buffer)
 	return *buffer->is;
 }
 
-bool
-decoder_buffer_is_empty(const DecoderBuffer *buffer)
-{
-	return buffer->consumed == buffer->length;
-}
-
 bool
 decoder_buffer_is_full(const DecoderBuffer *buffer)
 {
diff --git a/src/decoder/DecoderBuffer.hxx b/src/decoder/DecoderBuffer.hxx
index f295eb0b5..0e4b1d5ce 100644
--- a/src/decoder/DecoderBuffer.hxx
+++ b/src/decoder/DecoderBuffer.hxx
@@ -58,10 +58,6 @@ gcc_pure
 const InputStream &
 decoder_buffer_get_stream(const DecoderBuffer *buffer);
 
-gcc_pure
-bool
-decoder_buffer_is_empty(const DecoderBuffer *buffer);
-
 gcc_pure
 bool
 decoder_buffer_is_full(const DecoderBuffer *buffer);