diff --git a/library/pk.c b/library/pk.c
index ea874b3..a1e278e 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -508,8 +508,7 @@
     PK_VALIDATE_RET( prv != NULL );
 
     if( pub->pk_info == NULL ||
-        prv->pk_info == NULL ||
-        prv->pk_info->check_pair_func == NULL )
+        prv->pk_info == NULL )
     {
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
     }