diff --git a/cddl/contrib/opensolaris/common/ctf/ctf_lookup.c b/cddl/contrib/opensolaris/common/ctf/ctf_lookup.c
index 5912cc1a36e8..cd9c71436938 100644
--- a/cddl/contrib/opensolaris/common/ctf/ctf_lookup.c
+++ b/cddl/contrib/opensolaris/common/ctf/ctf_lookup.c
@@ -132,9 +132,9 @@ ctf_lookup_by_name(ctf_file_t *fp, const char *name)
 			continue; /* skip qualifier keyword */
 
 		for (lp = fp->ctf_lookups; lp->ctl_prefix != NULL; lp++) {
-			if ((size_t)(q - p) >= lp->ctl_len &&
-			    (lp->ctl_prefix[0] == '\0' ||
-			    strncmp(p, lp->ctl_prefix, (size_t)(q - p)) == 0)) {
+			if (lp->ctl_prefix[0] == '\0' ||
+			    ((size_t)(q - p) >= lp->ctl_len && strncmp(p,
+			    lp->ctl_prefix, (size_t)(q - p)) == 0)) {
 				for (p += lp->ctl_len; isspace(*p); p++)
 					continue; /* skip prefix and next ws */