diff -Naur x48-0.6.4.orig/src/debugger.c x48-0.6.4/src/debugger.c
--- x48-0.6.4.orig/src/debugger.c	2011-11-15 04:03:40.000000000 +0100
+++ x48-0.6.4/src/debugger.c	2020-06-23 21:33:16.071667987 +0200
@@ -1528,7 +1528,7 @@
   struct se *se_next;
 };
 
-char *
+void
 #ifdef __FunctionProto__
 get_stack (void)
 #else
diff -Naur x48-0.6.4.orig/src/x48_x11.c x48-0.6.4/src/x48_x11.c
--- x48-0.6.4.orig/src/x48_x11.c	2011-11-15 04:03:40.000000000 +0100
+++ x48-0.6.4/src/x48_x11.c	2020-06-23 21:33:32.132680745 +0200
@@ -3833,7 +3833,7 @@
 
 int last_button = -1;
 
-extern char *get_stack(void);
+extern void get_stack(void);
 
 int
 #ifdef __FunctionProto__