diff --git a/configure.ac b/configure.ac
index 58feccb..86dbe49 100644
--- a/configure.ac
+++ b/configure.ac
@@ -24,6 +24,7 @@ gl_INIT
 
 # Gettext
 AM_GNU_GETTEXT([external])
+AM_GNU_GETTEXT_VERSION(0.18)
 
 # Checks for libraries.
 OL_LIB_READLINE