diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index 0d4689d40619c394bab347e2f1007f7a9306e057..9ff67bd1bd2cc2d9bc2d853cf00e870ec36cb33a 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -61,6 +61,7 @@ static const char avi_headers[][8] = {
     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', ' ' },
     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 'X' },
     { 'R', 'I', 'F', 'F',    'A', 'V', 'I', 0x19},
+    { 'O', 'N', '2', ' ',    'O', 'N', '2', 'f' },
     { 0 }
 };