diff --git a/library/pk.c b/library/pk.c
index d30205c..d731d5b 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -418,7 +418,7 @@
         return 0;
     }
 
-    *hash_len = mbedtls_hash_info_get_size(md_alg);
+    *hash_len = mbedtls_md_get_size_from_type(md_alg);
 
     if (*hash_len == 0) {
         return -1;