1 files changed, 5 insertions, 0 deletions
diff --git a/src/nvim/api/private/helpers.c b/src/nvim/api/private/helpers.c
index ddcfff0097..2b107a3f27 100644
--- a/src/nvim/api/private/helpers.c
+++ b/src/nvim/api/private/helpers.c
@@ -1384,6 +1384,11 @@ void add_user_command(String name, Object command, Dict(user_command) *opts, int
   LuaRef luaref = LUA_NOREF;
   LuaRef compl_luaref = LUA_NOREF;
 
+  if (!uc_validate_name(name.data)) {
+    api_set_error(err, kErrorTypeValidation, "Invalid command name");
+    goto err;
+  }
+
   if (mb_islower(name.data[0])) {
     api_set_error(err, kErrorTypeValidation, "'name' must begin with an uppercase letter");
     goto err;