diff --git a/configure.ac b/configure.ac
index 1daa614..0d62f48 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,7 +15,7 @@
 #                 changes to the signature and the semantic)
 #  ? :+1 : ?   == just internal changes
 # CURRENT : REVISION : AGE
-LIBPLIST_SO_VERSION=3:0:0
+LIBPLIST_SO_VERSION=4:0:1
 
 AC_SUBST(LIBPLIST_SO_VERSION)