diff --git a/libopenarc/arc-canon.c b/libopenarc/arc-canon.c
index b2d66b0a..6251f5b9 100644
--- a/libopenarc/arc-canon.c
+++ b/libopenarc/arc-canon.c
@@ -2135,16 +2135,20 @@ arc_parse_canon_t(unsigned char *tag, arc_canon_t *hdr_canon,
 		return ARC_STAT_INVALID;
 
 	token = strtok_r(tag, "/", &last);
+	if (token == NULL)
+		return ARC_STAT_INVALID;
+		
 	code = arc_name_to_code(canonicalizations, token);
-
 	if (code == -1)
 		return ARC_STAT_INVALID;
 
 	*hdr_canon = (arc_canon_t) code;
 
 	token = strtok_r(NULL, "/", &last);
-	code = arc_name_to_code(canonicalizations, token);
+	if (token == NULL)
+		return ARC_STAT_INVALID;
 
+	code = arc_name_to_code(canonicalizations, token);
 	if (code == -1)
 		return ARC_STAT_INVALID;