diff --git a/modules/desktop_capture/win/full_screen_win_application_handler.cc b/modules/desktop_capture/win/full_screen_win_application_handler.cc
index f7047dba06..4222dfc01e 100644
--- a/modules/desktop_capture/win/full_screen_win_application_handler.cc
+++ b/modules/desktop_capture/win/full_screen_win_application_handler.cc
@@ -11,6 +11,7 @@
 #include "modules/desktop_capture/win/full_screen_win_application_handler.h"
 
 #include <algorithm>
+#include <cwctype>
 #include <memory>
 #include <string>
 #include <vector>