diff --git a/gst/pnm/gstpnmutils.h b/gst/pnm/gstpnmutils.h
index ed906521d4..6e99e72098 100644
--- a/gst/pnm/gstpnmutils.h
+++ b/gst/pnm/gstpnmutils.h
@@ -23,10 +23,10 @@
 #include <glib.h>
 #include <glib-object.h>
 
-#define MIME_BM "image/x-image-bitmap"
-#define MIME_GM "image/x-image-graymap"
-#define MIME_PM "image/x-image-pixmap"
-#define MIME_AM "image/x-image-anymap"
+#define MIME_BM "image/x-portable-bitmap"
+#define MIME_GM "image/x-portable-graymap"
+#define MIME_PM "image/x-portable-pixmap"
+#define MIME_AM "image/x-portable-anymap"
 #define MIME_ALL MIME_BM "; " MIME_GM "; " MIME_PM "; " MIME_AM
 
 typedef enum