diff --git a/aegisub/audio_display.cpp b/aegisub/audio_display.cpp
index 6188a40ea..dfe07aab3 100644
--- a/aegisub/audio_display.cpp
+++ b/aegisub/audio_display.cpp
@@ -165,7 +165,7 @@ void AudioDisplay::UpdateImage(bool weak) {
 
 	// Set image as needing to be redrawn
 	needImageUpdate = true;
-	if (!needImageUpdateWeak) needImageUpdateWeak = weak;
+	if (needImageUpdateWeak) needImageUpdateWeak = weak;
 	Refresh(false);
 }