diff --git a/configure.ac b/configure.ac
index 3fec5a598..1207064d0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -390,7 +390,9 @@ dnl it should be safe to re-edit 0.40 back down to 0.23
 use_nls=no
 if test "x$enable_nls" = "xyes" ; then
     use_nls=yes
-    IT_PROG_INTLTOOL([0.35.0],[no-xml])
+    m4_ifdef([IT_PROG_INTLTOOL],
+             [IT_PROG_INTLTOOL([0.35.0],[no-xml])],
+             [AC_MSG_ERROR("--enable-nls requires intltool to be installed.")])
     AC_CHECK_HEADERS([libintl.h])
     GETTEXT_PACKAGE=transmission-gtk
     AC_SUBST(GETTEXT_PACKAGE)