diff --git a/multimedia/gstreamer1-plugins-bad/files/patch-ext_opencv_gstcvdilateerode.cpp b/multimedia/gstreamer1-plugins-bad/files/patch-ext_opencv_gstcvdilateerode.cpp
new file mode 100644
index 000000000000..632a5b18225a
--- /dev/null
+++ b/multimedia/gstreamer1-plugins-bad/files/patch-ext_opencv_gstcvdilateerode.cpp
@@ -0,0 +1,11 @@
+--- ext/opencv/gstcvdilateerode.cpp.orig	2021-08-02 14:37:33 UTC
++++ ext/opencv/gstcvdilateerode.cpp
+@@ -89,7 +89,7 @@ gst_cv_dilate_erode_get_type (void)
+ {
+   static volatile gsize opencv_dilate_erode_type = 0;
+ 
+-  if (g_once_init_enter (&opencv_dilate_erode_type)) {
++  if (g_once_init_enter ((unsigned long *)&opencv_dilate_erode_type)) {
+     GType _type;
+     static const GTypeInfo opencv_dilate_erode_info = {
+       sizeof (GstCvDilateErodeClass),