diff --git a/configure.ac b/configure.ac
index d23e2ac..07169c8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT([libzbxmodbus], [0.4])
+AC_INIT([libzbxmodbus], [0.5)
 AM_INIT_AUTOMAKE([foreign -Wall -Werror])
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_SRCDIR([src/modbus.c])