diff --git a/Source/GUI/Plots.h b/Source/GUI/Plots.h
index ce24e2fe4..c0586e4c8 100755
--- a/Source/GUI/Plots.h
+++ b/Source/GUI/Plots.h
@@ -23,6 +23,7 @@ class Plot;
 class PlotScaleWidget;
 class PlayerControl;
 class YMinMaxSelector;
+class QToolButton;
 
 void showEditFrameCommentsDialog(QWidget* parentWidget, FileInformation* info, CommonStats* stats, size_t frameIndex);