diff --git a/sys/niimaqdx/gstniimaqdx.c b/sys/niimaqdx/gstniimaqdx.c
index e976d81..c0ef47c 100644
--- a/sys/niimaqdx/gstniimaqdx.c
+++ b/sys/niimaqdx/gstniimaqdx.c
@@ -581,6 +581,8 @@ gst_niimaqdxsrc_reset (GstNiImaqDxSrc * niimaqdxsrc)
   niimaqdxsrc->width = 0;
   niimaqdxsrc->height = 0;
   niimaqdxsrc->dx_row_stride = 0;
+  niimaqdxsrc->caps_info = NULL;
+  niimaqdxsrc->pixel_format[0] = 0;
   niimaqdxsrc->start_time = NULL;
   niimaqdxsrc->start_time_sent = FALSE;
   niimaqdxsrc->base_time = GST_CLOCK_TIME_NONE;
@@ -662,11 +664,16 @@ gst_niimaqdxsrc_fill (GstPushSrc * src, GstBuffer * buf)
     }
   }
 
+  if (niimaqdxsrc->caps_info == NULL) {
+    GST_ELEMENT_ERROR (niimaqdxsrc, RESOURCE, FAILED,
+        ("Failed to create caps, possibly unsupported format (%s).",
+            niimaqdxsrc->pixel_format), (NULL));
+    return GST_FLOW_ERROR;
+  }
+
   GST_LOG_OBJECT (niimaqdxsrc, "Copying IMAQ buffer #%d, buffersize %d",
       niimaqdxsrc->cumbufnum, gst_buffer_get_size (buf));
 
-  g_assert (niimaqdxsrc->caps_info != NULL);
-
   do_align_stride =
       (niimaqdxsrc->dx_row_stride % niimaqdxsrc->caps_info->row_multiple) != 0;
 
diff --git a/sys/niimaqdx/gstniimaqdx.h b/sys/niimaqdx/gstniimaqdx.h
index a1c3b11..866068d 100644
--- a/sys/niimaqdx/gstniimaqdx.h
+++ b/sys/niimaqdx/gstniimaqdx.h
@@ -66,6 +66,7 @@ struct _GstNiImaqDxSrc {
   gboolean bayer_as_gray;
 
   /* image info */
+  char pixel_format[IMAQDX_MAX_API_STRING_LENGTH];
   int width;
   int height;
   int dx_row_stride;