diff --git a/m4/pkg-config.m4 b/m4/pkg-config.m4
index 1355c0c9..63686aac 100644
--- a/m4/pkg-config.m4
+++ b/m4/pkg-config.m4
@@ -13,6 +13,7 @@ m4_if([$3], [yes],
     ])
 m4_if([$4], [no], [ac_cv_want_[]$1=yes])
 
+test "x$ac_cv_want_[]$1" = "x" && ac_cv_want_[]$1="check"
 case "x$ac_cv_want_[]$1" in
     "xno")
             ac_cv_[]$1=no