diff --git a/configure.ac b/configure.ac
index 37b298e..f70717a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -55,7 +55,7 @@
                [AC_MSG_FAILURE(
                  [--with-pthreads was specified, but unable to be used])])])
        have_pthreads="$acx_pthread_ok"])
-AM_CONDITIONAL([HAVE_PTHREADS],[test "x$have_pthreads" == "xyes"])
+AM_CONDITIONAL([HAVE_PTHREADS],[test "x$have_pthreads" = "xyes"])
 AC_SUBST(PTHREAD_CFLAGS)
 AC_SUBST(PTHREAD_LIBS)