diff --git a/m4/exosip.m4 b/m4/exosip.m4
index f5ebdded8053a8778f8f8b4dddeb55287aadb03c..b412e1c22c464d3fa9adc927829a681024ac0c1f 100644
--- a/m4/exosip.m4
+++ b/m4/exosip.m4
@@ -14,10 +14,9 @@ SONAME_MICRO_VERSION=0
 
 dnl program extension
 EXOSIP_VERSION=$EXOSIP_MAJOR_VERSION.$EXOSIP_MINOR_VERSION.$EXOSIP_MICRO_VERSION
-
 LIBEXOSIP_SO_VERSION=$SONAME_MAJOR_VERSION:$SONAME_MINOR_VERSION:$SONAME_MICRO_VERSION
 
-AC_SUBST(LIBEXOSIP_SO_VERSION, $LIBEXOSIP_SO_VERSION)
+AC_SUBST(LIBEXOSIP_SO_VERSION)
 AC_SUBST(EXOSIP_VERSION)
 
 dnl support for linux-thread or posix thread (pthread.h)