diff -Naur Src.orig/wmFrog.c Src/wmFrog.c
--- Src.orig/wmFrog.c	2010-12-01 19:48:50.000000000 +0100
+++ Src/wmFrog.c	2020-03-01 15:54:30.428083446 +0100
@@ -77,6 +77,12 @@
 char* folder;
 int needsUpdate = 1;
 
+Display		*display;
+Window          Root;
+Window          iconwin, win;
+int             screen; 
+int             DisplayDepth;
+
 /*
  *   main
  */
diff -Naur Src.orig/xutils.h Src/xutils.h
--- Src.orig/xutils.h	2010-08-04 20:28:46.000000000 +0200
+++ Src/xutils.h	2020-03-01 15:54:37.027084834 +0100
@@ -18,11 +18,11 @@
 /*
  *   Global variable
  */
-Display		*display;
-Window          Root;
-Window          iconwin, win;
-int             screen; 
-int             DisplayDepth;
+extern Display		*display;
+extern Window          Root;
+extern Window          iconwin, win;
+extern int             screen; 
+extern int             DisplayDepth;