2 files changed, 29 insertions, 5 deletions
diff --git a/src/class.c b/src/class.c
index e8f9b7638..bbf64e8ea 100644
--- a/src/class.c
+++ b/src/class.c
@@ -575,7 +575,7 @@ mrb_vm_define_class(mrb_state *mrb, mrb_value outer, mrb_value super, mrb_sym id
 MRB_API mrb_bool
 mrb_class_defined(mrb_state *mrb, const char *name)
 {
-  mrb_sym sym = mrb_check_intern_cstr(mrb, name);
+  mrb_sym sym = mrb_intern_check_cstr(mrb, name);
   if (!sym) return FALSE;
   return mrb_const_defined(mrb, mrb_obj_value(mrb->object_class), sym);
 }
@@ -589,7 +589,7 @@ mrb_class_defined_id(mrb_state *mrb, mrb_sym name)
 MRB_API mrb_bool
 mrb_class_defined_under(mrb_state *mrb, struct RClass *outer, const char *name)
 {
-  mrb_sym sym = mrb_check_intern_cstr(mrb, name);
+  mrb_sym sym = mrb_intern_check_cstr(mrb, name);
   if (!sym) return FALSE;
   return mrb_const_defined_at(mrb, mrb_obj_value(outer), sym);
 }
diff --git a/src/symbol.c b/src/symbol.c
index 9683d2f72..18ea49da5 100644
--- a/src/symbol.c
+++ b/src/symbol.c
@@ -268,7 +268,7 @@ mrb_intern_str(mrb_state *mrb, mrb_value str)
 }
 
 MRB_API mrb_sym
-mrb_check_intern(mrb_state *mrb, const char *name, size_t len)
+mrb_intern_check(mrb_state *mrb, const char *name, size_t len)
 {
   mrb_sym sym;
 
@@ -278,16 +278,40 @@ mrb_check_intern(mrb_state *mrb, const char *name, size_t len)
   return 0;
 }
 
+MRB_API mrb_value
+mrb_check_intern(mrb_state *mrb, const char *name, size_t len)
+{
+  mrb_sym sym = mrb_intern_check(mrb, name, len);
+  if (sym == 0) return mrb_nil_value();
+  return mrb_symbol_value(sym);
+}
+
 MRB_API mrb_sym
+mrb_intern_check_cstr(mrb_state *mrb, const char *name)
+{
+  return mrb_intern_check(mrb, name, strlen(name));
+}
+
+MRB_API mrb_value
 mrb_check_intern_cstr(mrb_state *mrb, const char *name)
 {
-  return mrb_check_intern(mrb, name, strlen(name));
+  mrb_sym sym = mrb_intern_check_cstr(mrb, name);
+  if (sym == 0) return mrb_nil_value();
+  return mrb_symbol_value(sym);
 }
 
 MRB_API mrb_sym
+mrb_intern_check_str(mrb_state *mrb, mrb_value str)
+{
+  return mrb_intern_check(mrb, RSTRING_PTR(str), RSTRING_LEN(str));
+}
+
+MRB_API mrb_value
 mrb_check_intern_str(mrb_state *mrb, mrb_value str)
 {
-  return mrb_check_intern(mrb, RSTRING_PTR(str), RSTRING_LEN(str));
+  mrb_sym sym = mrb_intern_check_str(mrb, str);
+  if (sym == 0) return mrb_nil_value();
+  return mrb_symbol_value(sym);
 }
 
 static const char*