diff --git a/code/client/cl_avi.c b/code/client/cl_avi.c
index 12cde119..b03adead 100644
--- a/code/client/cl_avi.c
+++ b/code/client/cl_avi.c
@@ -555,7 +555,7 @@ void CL_WriteAVIAudioFrame( const byte *pcmBuffer, int size )
 
     afd.numAudioFrames++;
     afd.moviSize += ( chunkSize + paddingSize );
-    afd.a.totalBytes =+ bytesInBuffer;
+    afd.a.totalBytes += bytesInBuffer;
 
     // Index
     bufIndex = 0;