diff --git a/configure.in b/configure.in
index 4825e2a..ec4375d 100644
--- a/configure.in
+++ b/configure.in
@@ -41,7 +41,7 @@ XTRA=""
 AC_ARG_ENABLE(fltk-client,
      [  --enable-fltk-client    build the FLTK test client.])
 
-if test "x$enable_fltk_client" != "no" ; then
+if test "x$enable_fltk_client" != "xno" ; then
      AC_CHECK_LIB(fltk,main,
          [ XTRA="$XTRA jack_fltk_client" ],
          [ AC_MSG_ERROR([*** you can't build the FLTK client without the FLTK library])],