diff --git a/library/pk.c b/library/pk.c
index af4a302..f083b86 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -166,7 +166,7 @@
     if( ( md_info = md_info_from_type( md_alg ) ) == NULL )
         return( -1 );
 
-    *hash_len = md_info->size;
+    *hash_len = md_get_size( md_info );
     return( 0 );
 }