diff --git a/gst/flv/gstflvmux.c b/gst/flv/gstflvmux.c
index c427f529cc..f2b9688cd2 100644
--- a/gst/flv/gstflvmux.c
+++ b/gst/flv/gstflvmux.c
@@ -1106,6 +1106,29 @@ gst_flv_mux_write_header (GstFlvMux * mux)
   GSList *l;
   GstFlowReturn ret;
 
+  /* if not streaming, check if downstream is seekable */
+  if (!mux->streamable) {
+    gboolean seekable;
+    GstQuery *query;
+
+    query = gst_query_new_seeking (GST_FORMAT_BYTES);
+    if (gst_pad_peer_query (mux->srcpad, query)) {
+      gst_query_parse_seeking (query, NULL, &seekable, NULL, NULL);
+      GST_INFO_OBJECT (mux, "downstream is %sseekable", seekable ? "" : "not ");
+      if (!seekable) {
+        mux->streamable = TRUE;
+        g_object_notify (G_OBJECT (mux), "streamable");
+        GST_WARNING_OBJECT (mux, "downstream is not seekable, but "
+            "streamable=false. Will ignore that and create streamable output "
+            "instead");
+      }
+    } else {
+      /* have to assume seeking is supported if query not handled downstream */
+      /* FIXME 0.11: change to query not handled => seeking not supported */
+      GST_WARNING_OBJECT (mux, "downstream did not handle seeking query");
+    }
+  }
+
   header = gst_flv_mux_create_header (mux);
   metadata = gst_flv_mux_create_metadata (mux, TRUE);
   video_codec_data = NULL;