diff --git a/lib/krb5/pac.c b/lib/krb5/pac.c
index 84015448c..b154c17f4 100644
--- a/lib/krb5/pac.c
+++ b/lib/krb5/pac.c
@@ -231,7 +231,7 @@ HMAC_MD5_any_checksum(krb5_context context,
     }
 
     result->cksumtype = CKSUMTYPE_HMAC_MD5;
-    iov.data.data = (void *)data;
+    iov.data.data = rk_UNCONST(data);
     iov.data.length = len;
     iov.flags = KRB5_CRYPTO_TYPE_DATA;