diff --git a/gst-libs/gst/vaapi/gstvaapidisplay.c b/gst-libs/gst/vaapi/gstvaapidisplay.c
index 7c6588afb7..ad6ebcbe22 100644
--- a/gst-libs/gst/vaapi/gstvaapidisplay.c
+++ b/gst-libs/gst/vaapi/gstvaapidisplay.c
@@ -649,8 +649,11 @@ ensure_image_formats (GstVaapiDisplay * display)
   gint i, n;
   gboolean success = FALSE;
 
-  if (priv->image_formats)
+  GST_VAAPI_DISPLAY_LOCK (display);
+  if (priv->image_formats) {
+    GST_VAAPI_DISPLAY_UNLOCK (display);
     return TRUE;
+  }
 
   priv->image_formats = g_array_new (FALSE, FALSE, sizeof (GstVaapiFormatInfo));
   if (!priv->image_formats)
@@ -676,6 +679,7 @@ ensure_image_formats (GstVaapiDisplay * display)
 
 cleanup:
   g_free (formats);
+  GST_VAAPI_DISPLAY_UNLOCK (display);
   return success;
 }
 
@@ -690,8 +694,11 @@ ensure_subpicture_formats (GstVaapiDisplay * display)
   guint i, n;
   gboolean success = FALSE;
 
-  if (priv->subpicture_formats)
+  GST_VAAPI_DISPLAY_LOCK (display);
+  if (priv->subpicture_formats) {
+    GST_VAAPI_DISPLAY_UNLOCK (display);
     return TRUE;
+  }
 
   priv->subpicture_formats =
       g_array_new (FALSE, FALSE, sizeof (GstVaapiFormatInfo));
@@ -725,6 +732,7 @@ ensure_subpicture_formats (GstVaapiDisplay * display)
 cleanup:
   g_free (formats);
   g_free (flags);
+  GST_VAAPI_DISPLAY_UNLOCK (display);
   return success;
 }