diff --git a/src/globals.h b/src/globals.h
index 33082d5..87f7b0b 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1724,6 +1724,9 @@
 
 // Used for checking if local variables or arguments used in a lambda.
 EXTERN int *eval_lavars_used INIT(= NULL);
+
+// Only filled for Win32.
+EXTERN char windowsVersion[20] INIT(= {0});
 #endif
 
 #ifdef MSWIN