diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 1eb6d585ea2dd8df45882c2a1ea55603184a2e3e..8839654fa25d013a86fe6eead22ef6f6aaaeeef9 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -919,6 +919,8 @@ static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
         break;
     }
 #endif
+    default:
+        return -1;
     }
 
     *buf = pkt_data;