diff --git a/gst-libs/gst/video/convertframe.c b/gst-libs/gst/video/convertframe.c
index f0a890b936..4155e20df4 100644
--- a/gst-libs/gst/video/convertframe.c
+++ b/gst-libs/gst/video/convertframe.c
@@ -552,7 +552,7 @@ done:
   g_mutex_unlock (&context->mutex);
 }
 
-static void
+static GstFlowReturn
 convert_frame_new_preroll_callback (GstElement * sink,
     GstVideoConvertSampleContext * context)
 {
@@ -577,6 +577,8 @@ convert_frame_new_preroll_callback (GstElement * sink,
 
 done:
   g_mutex_unlock (&context->mutex);
+
+  return GST_FLOW_OK;
 }
 
 /**
diff --git a/tests/examples/app/appsink-src.c b/tests/examples/app/appsink-src.c
index 2b274e8ebd..9a191e02eb 100644
--- a/tests/examples/app/appsink-src.c
+++ b/tests/examples/app/appsink-src.c
@@ -17,7 +17,7 @@ typedef struct
 
 /* called when the appsink notifies us that there is a new buffer ready for
  * processing */
-static void
+static GstFlowReturn
 on_new_sample_from_sink (GstElement * elt, ProgramData * data)
 {
   GstSample *sample;
@@ -36,7 +36,7 @@ on_new_sample_from_sink (GstElement * elt, ProgramData * data)
 
   /* get source an push new buffer */
   source = gst_bin_get_by_name (GST_BIN (data->sink), "testsource");
-  gst_app_src_push_buffer (GST_APP_SRC (source), app_buffer);
+  return gst_app_src_push_buffer (GST_APP_SRC (source), app_buffer);
 }
 
 /* called when we get a GstMessage from the source pipeline when we get EOS, we