diff --git a/library/pkparse.c b/library/pkparse.c
index 3bb5f7b..edebf92 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -928,7 +928,7 @@
             ret = pk_use_ecparams(&alg_params, pk);
         }
         if (ret == 0) {
-            ret = pk_ecc_set_pubkey(pk, *p, end - *p);
+            ret = pk_ecc_set_pubkey(pk, *p, (size_t) (end - *p));
             *p += end - *p;
         }
     } else
@@ -1233,7 +1233,7 @@
                                          MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
             }
 
-            if ((ret = pk_ecc_set_pubkey(pk, p, end2 - p)) == 0) {
+            if ((ret = pk_ecc_set_pubkey(pk, p, (size_t) (end2 - p))) == 0) {
                 pubkey_done = 1;
             } else {
                 /*