diff --git a/cddl/contrib/opensolaris/common/ctf/ctf_lookup.c b/cddl/contrib/opensolaris/common/ctf/ctf_lookup.c
index f8fa72435591..aa58663309b6 100644
--- a/cddl/contrib/opensolaris/common/ctf/ctf_lookup.c
+++ b/cddl/contrib/opensolaris/common/ctf/ctf_lookup.c
@@ -59,10 +59,12 @@ isqualifier(const char *s, size_t len)
 	};
 
 	int h = s[len - 1] + (int)len - 105;
-	const struct qual *qp = &qhash[h];
+	const struct qual *qp;
 
-	return (h >= 0 && h < sizeof (qhash) / sizeof (qhash[0]) &&
-	    len == qp->q_len && strncmp(qp->q_name, s, qp->q_len) == 0);
+	if (h < 0 || h >= sizeof (qhash) / sizeof (qhash[0]))
+		return (0);
+	qp = &qhash[h];
+	return (len == qp->q_len && strncmp(qp->q_name, s, qp->q_len) == 0);
 }
 
 /*