diff --git a/configure.in b/configure.in
index b2f15eb..6c9b8dc 100644
--- a/configure.in
+++ b/configure.in
@@ -18,7 +18,7 @@ AC_CONFIG_SRCDIR([lib/lbfgs.c])
 dnl ------------------------------------------------------------------
 dnl Initialization for automake
 dnl ------------------------------------------------------------------
-AM_INIT_AUTOMAKE(liblbfgs, 1.5)
+AM_INIT_AUTOMAKE(liblbfgs, 1.6)
 AC_CONFIG_HEADERS(config.h)
 AM_MAINTAINER_MODE