diff --git a/include/mbedtls/asn1.h b/include/mbedtls/asn1.h
index 07fbe56..33b3004 100644
--- a/include/mbedtls/asn1.h
+++ b/include/mbedtls/asn1.h
@@ -501,8 +501,8 @@
 int mbedtls_asn1_traverse_sequence_of(
     unsigned char **p,
     const unsigned char *end,
-    uint8_t tag_must_mask, uint8_t tag_must_val,
-    uint8_t tag_may_mask, uint8_t tag_may_val,
+    unsigned char tag_must_mask, unsigned char tag_must_val,
+    unsigned char tag_may_mask, unsigned char tag_may_val,
     int (*cb)( void *ctx, int tag,
                unsigned char* start, size_t len ),
     void *ctx );