diff --git a/gst/qtdemux/qtdemux.c b/gst/qtdemux/qtdemux.c
index c54ef39d8b..243f462a4d 100644
--- a/gst/qtdemux/qtdemux.c
+++ b/gst/qtdemux/qtdemux.c
@@ -3513,8 +3513,8 @@ qtdemux_parse_trak (GstQTDemux * qtdemux, GNode * trak)
             break;
           GST_DEBUG_OBJECT (qtdemux, "found colr");
           /* try to extract colour space info */
-          if (QT_UINT8 (colr->data + 8) == 1) {
-            switch (QT_UINT32 (colr->data + 11)) {
+          if (QT_UINT8 ((guint8 *) colr->data + 8) == 1) {
+            switch (QT_UINT32 ((guint8 *) colr->data + 11)) {
               case 16:
                 fourcc = GST_MAKE_FOURCC ('s', 'R', 'G', 'B');
                 break;
@@ -3539,7 +3539,7 @@ qtdemux_parse_trak (GstQTDemux * qtdemux, GNode * trak)
 
           /* indicate possible fields in caps */
           if (field) {
-            data = field->data + 8;
+            data = (guint8 *) field->data + 8;
             if (*data != 1)
               gst_caps_set_simple (stream->caps, "fields", G_TYPE_INT,
                   (gint) * data, NULL);
@@ -4041,8 +4041,8 @@ qtdemux_tag_add_covr (GstQTDemux * qtdemux, const char *tag1, const char *dummy,
     type = QT_UINT32 ((guint8 *) data->data + 8);
     GST_DEBUG_OBJECT (qtdemux, "have covr tag, type=%d,len=%d", type, len);
     if ((type == 0x0000000d || type == 0x0000000e) && len > 16) {
-      if ((buf = gst_tag_image_data_to_image_buffer (data->data + 16, len - 16,
-                  GST_TAG_IMAGE_TYPE_NONE))) {
+      if ((buf = gst_tag_image_data_to_image_buffer ((guint8 *) data->data + 16,
+                  len - 16, GST_TAG_IMAGE_TYPE_NONE))) {
         GST_DEBUG_OBJECT (qtdemux, "adding tag size %d", len - 16);
         gst_tag_list_add (qtdemux->tag_list, GST_TAG_MERGE_REPLACE,
             tag1, buf, NULL);