diff --git a/editor/editor_file_dialog.cpp b/editor/editor_file_dialog.cpp
index be01df76f76..1f437408585 100644
--- a/editor/editor_file_dialog.cpp
+++ b/editor/editor_file_dialog.cpp
@@ -680,7 +680,12 @@ void EditorFileDialog::update_file_name() {
 		String filter_str = filters[idx];
 		String file_str = file->get_text();
 		String base_name = file_str.get_basename();
-		file_str = base_name + "." + filter_str.split(";")[1].strip_edges().to_lower();
+		Vector<String> filter_substr = filter_str.split(";");
+		if (filter_substr.size() >= 2) {
+			file_str = base_name + "." + filter_substr[1].strip_edges().to_lower();
+		} else {
+			file_str = base_name + "." + filter_str.get_extension().strip_edges().to_lower();
+		}
 		file->set_text(file_str);
 	}
 }