diff --git a/dlls/msvfw32/msvideo_main.c b/dlls/msvfw32/msvideo_main.c
index f4184813369..ea38e0f94df 100644
--- a/dlls/msvfw32/msvideo_main.c
+++ b/dlls/msvfw32/msvideo_main.c
@@ -1373,7 +1373,7 @@ LPVOID VFWAPI ICSeqCompressFrame(PCOMPVARS pc, UINT uiFlags, LPVOID lpBits, BOOL
     icComp->lFrameNum = pc->lFrame++;
     icComp->lpOutput = pc->lpBitsOut;
     icComp->lpPrev = pc->lpBitsPrev;
-    ret = ICSendMessage(pc->hic, ICM_COMPRESS, (DWORD_PTR)icComp, sizeof(icComp));
+    ret = ICSendMessage(pc->hic, ICM_COMPRESS, (DWORD_PTR)icComp, sizeof(*icComp));
 
     if (icComp->dwFlags & AVIIF_KEYFRAME)
     {