diff --git a/libavdevice/vfwcap.c b/libavdevice/vfwcap.c
index 6a923d9957..e2ab276c2e 100644
--- a/libavdevice/vfwcap.c
+++ b/libavdevice/vfwcap.c
@@ -328,11 +328,14 @@ static int vfw_read_header(AVFormatContext *s)
     }
 
     if (ctx->video_size) {
-        ret = av_parse_video_size(&bi->bmiHeader.biWidth, &bi->bmiHeader.biHeight, ctx->video_size);
+        int w, h;
+        ret = av_parse_video_size(&w, &h, ctx->video_size);
         if (ret < 0) {
             av_log(s, AV_LOG_ERROR, "Couldn't parse video size.\n");
             goto fail;
         }
+        bi->bmiHeader.biWidth  = w;
+        bi->bmiHeader.biHeight = h;
     }
 
     if (0) {