diff --git a/sys/v4l2/gstv4l2object.c b/sys/v4l2/gstv4l2object.c
index 47a8dd7583..dc7585cda0 100644
--- a/sys/v4l2/gstv4l2object.c
+++ b/sys/v4l2/gstv4l2object.c
@@ -1577,10 +1577,13 @@ gst_v4l2_object_get_all_caps (void)
 {
   static GstCaps *caps = NULL;
 
-  if (caps == NULL)
-    caps = gst_v4l2_object_get_caps_helper (GST_V4L2_ALL);
+  if (g_once_init_enter (&caps)) {
+    GstCaps *all_caps = gst_v4l2_object_get_caps_helper (GST_V4L2_ALL);
+    GST_MINI_OBJECT_FLAG_SET (all_caps, GST_MINI_OBJECT_FLAG_MAY_BE_LEAKED);
+    g_once_init_leave (&caps, all_caps);
+  }
 
-  return gst_caps_ref (caps);
+  return caps;
 }
 
 GstCaps *
@@ -1588,10 +1591,13 @@ gst_v4l2_object_get_raw_caps (void)
 {
   static GstCaps *caps = NULL;
 
-  if (caps == NULL)
-    caps = gst_v4l2_object_get_caps_helper (GST_V4L2_RAW);
+  if (g_once_init_enter (&caps)) {
+    GstCaps *raw_caps = gst_v4l2_object_get_caps_helper (GST_V4L2_RAW);
+    GST_MINI_OBJECT_FLAG_SET (raw_caps, GST_MINI_OBJECT_FLAG_MAY_BE_LEAKED);
+    g_once_init_leave (&caps, raw_caps);
+  }
 
-  return gst_caps_ref (caps);
+  return caps;
 }
 
 GstCaps *
@@ -1599,10 +1605,13 @@ gst_v4l2_object_get_codec_caps (void)
 {
   static GstCaps *caps = NULL;
 
-  if (caps == NULL)
-    caps = gst_v4l2_object_get_caps_helper (GST_V4L2_CODEC);
+  if (g_once_init_enter (&caps)) {
+    GstCaps *codec_caps = gst_v4l2_object_get_caps_helper (GST_V4L2_CODEC);
+    GST_MINI_OBJECT_FLAG_SET (codec_caps, GST_MINI_OBJECT_FLAG_MAY_BE_LEAKED);
+    g_once_init_leave (&caps, codec_caps);
+  }
 
-  return gst_caps_ref (caps);
+  return caps;
 }
 
 /* collect data for the given caps