diff -Naur src.orig/wmgeneral.h src/wmgeneral.h
--- src.orig/wmgeneral.h	2017-12-06 15:00:16.000000000 +0100
+++ src/wmgeneral.h	2020-03-01 16:03:18.293199660 +0100
@@ -38,7 +38,7 @@
  /* Global variable */
 /*******************/
 
-Display		*display;
+extern Display		*display;
 
   /***********************/
  /* Function Prototypes */
diff -Naur src.orig/wmsysmon.c src/wmsysmon.c
--- src.orig/wmsysmon.c	2017-12-06 15:00:16.000000000 +0100
+++ src/wmsysmon.c	2020-03-01 16:03:32.992203044 +0100
@@ -138,6 +138,7 @@
 time_t	curtime;
 time_t	prevtime;
 
+Display		*display;
 
 kernel_versions Get_Kernel_version(void);
 void usage(void);