1 files changed, 4 insertions, 1 deletions
diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index 54b36d06d8..124fce58b6 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -1179,7 +1179,10 @@ int nlua_call(lua_State *lstate)
   size_t name_len;
   const char *name = luaL_checklstring(lstate, 1, &name_len);
   if (!nlua_is_deferred_safe() && !viml_func_is_fast(name)) {
-    return luaL_error(lstate, e_fast_api_disabled, "Vimscript function");
+    size_t length = MIN(strlen(name), 100) + sizeof("Vimscript function \"\"");
+    vim_snprintf(IObuff, length, "Vimscript function \"%s\"", name);
+    int ret = luaL_error(lstate, e_fast_api_disabled, IObuff);
+    return ret;
   }
 
   int nargs = lua_gettop(lstate) - 1;