diff --git a/Makefile.defs b/Makefile.defs
index 5f20bb19..7ff3fd41 100644
--- a/Makefile.defs
+++ b/Makefile.defs
@@ -1,9 +1,10 @@
+SVN_REV=r$(shell svnversion -n .)
 
 #version number
 VERSION = 0
 PATCHLEVEL = 10
 SUBLEVEL = 0
-EXTRAVERSION = 
+EXTRAVERSION ?= -$(SVN_REV)
 
 RELEASE=$(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)