2 files changed, 2 insertions, 1 deletions
diff --git a/src/class.c b/src/class.c
index 366bde96d..f517cc19a 100644
--- a/src/class.c
+++ b/src/class.c
@@ -502,6 +502,7 @@ mrb_mod_include(mrb_state *mrb, mrb_value klass)
   mrb_value mod;
 
   mrb_get_args(mrb, "o", &mod);
+  mrb_check_type(mrb, mod, MRB_TT_MODULE);
   mrb_include_module(mrb, mrb_class_ptr(klass), mrb_class_ptr(mod));
   return mod;
 }
diff --git a/src/vm.c b/src/vm.c
index 543b56c19..f2f59cfbb 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -268,7 +268,7 @@ localjump_error(mrb_state *mrb, const char *kind)
   mrb_value exc;
 
   snprintf(buf, 256, "unexpected %s", kind);
-  exc = mrb_exc_new(mrb, E_LOCALJUMP_ERROR, buf, sizeof(buf));
+  exc = mrb_exc_new(mrb, E_LOCALJUMP_ERROR, buf, strlen(buf));
   mrb->exc = mrb_object(exc);
 }