diff --git a/src/ui/dialog/filter-effects-dialog.cpp b/src/ui/dialog/filter-effects-dialog.cpp
index 60e72f6276f8f834dbb0ae198c3370a346b4de58..b7205a70c7bea3cad205172e59f0d27b8ec1ad09 100644
--- a/src/ui/dialog/filter-effects-dialog.cpp
+++ b/src/ui/dialog/filter-effects-dialog.cpp
@@ -2063,7 +2063,7 @@ void FilterEffectsDialog::PrimitiveList::draw_connection(const Cairo::RefPtr<Cai
         arc_radius = 6;
     }
 
-    if(res == input || (use_default && is_first)) {
+    if((res && res == input) || (use_default && is_first)) {
         // Draw straight connection to a standard input
         // Draw a lighter line for an implicit connection to a standard input
         const int tw = get_input_type_width();