diff --git a/src/gui/fileDialog.h b/src/gui/fileDialog.h
index 6c5f2faac..8d3ff787a 100644
--- a/src/gui/fileDialog.h
+++ b/src/gui/fileDialog.h
@@ -1,5 +1,6 @@
 #include "../ta-utils.h"
 #include "imgui.h"
+#include <functional>
 #include <vector>
 
 namespace pfd {