--- ./src/Makefile.in.orig	2005-12-14 23:56:18.000000000 +0100
+++ ./src/Makefile.in	2005-12-14 23:56:21.000000000 +0100
@@ -470,7 +470,7 @@
 
 install-exec-hook:
 		cd $(DESTDIR)$(bindir) && \
-			$(LN_S) pstree pstree.x11
+			$(LN_S) -f pstree pstree.x11
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.
 .NOEXPORT: