diff --git a/aegisub/src/visual_tool.cpp b/aegisub/src/visual_tool.cpp
index 9bdbf3f03..3d691e8ce 100644
--- a/aegisub/src/visual_tool.cpp
+++ b/aegisub/src/visual_tool.cpp
@@ -277,7 +277,7 @@ void VisualTool<FeatureType>::Commit(bool full, wxString message) {
 template<class FeatureType>
 AssDialogue* VisualTool<FeatureType>::GetActiveDialogueLine() {
 	AssDialogue *diag = grid->GetActiveLine();
-	if (grid->IsDisplayed(diag))
+	if (diag && grid->IsDisplayed(diag))
 		return diag;
 	return NULL;
 }