diff --git a/library/pk.c b/library/pk.c
index 1eab65a..462807c 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -24,6 +24,8 @@
 #include "pk_wrap.h"
 #include "pkwrite.h"
 
+#include "md_internal.h"
+
 #include "mbedtls/platform_util.h"
 #include "mbedtls/error.h"
 
@@ -358,15 +360,14 @@
  */
 static inline int pk_hashlen_helper( mbedtls_md_type_t md_alg, size_t *hash_len )
 {
-    const mbedtls_md_info_t *md_info;
-
     if( *hash_len != 0 )
         return( 0 );
 
-    if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
+    *hash_len = mbedtls_md_internal_get_size( md_alg );
+
+    if( *hash_len == 0 )
         return( -1 );
 
-    *hash_len = mbedtls_md_get_size( md_info );
     return( 0 );
 }