diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
index 77c7a1149fb..a8b520834c7 100644
--- a/gcc/config/rs6000/rs6000-call.c
+++ b/gcc/config/rs6000/rs6000-call.c
@@ -13490,7 +13490,7 @@ altivec_init_builtins (void)
     {
       def_builtin ("__builtin_altivec_stxvl", void_ftype_v16qi_pvoid_long,
 		   P9V_BUILTIN_STXVL);
-      def_builtin ("__builtin_xst_len_r", void_ftype_v16qi_pvoid_long,
+      def_builtin ("__builtin_altivec_xst_len_r", void_ftype_v16qi_pvoid_long,
 		   P9V_BUILTIN_XST_LEN_R);
     }