diff --git a/src/kernel.c b/src/kernel.c
index 25aa41baf..719f92b7e 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -510,7 +510,7 @@ mrb_method_missing(mrb_state *mrb, mrb_sym name, mrb_value self, mrb_value args)
* # ...
* end
* def method_missing(methId)
- * str = methId.id2name
+ * str = methId.to_s
* romanToInt(str)
* end
* end
diff --git a/src/string.c b/src/string.c
index e440bff8c..d442ff17d 100644
--- a/src/string.c
+++ b/src/string.c
@@ -1873,7 +1873,7 @@ mrb_str_init(mrb_state *mrb, mrb_value self)
* str.to_sym => symbol
*
* Returns the Symbol corresponding to str, creating the
- * symbol if it did not previously exist. See Symbol#id2name.
+ * symbol if it did not previously exist.
*
* "Koala".intern #=> :Koala
* s = 'cat'.to_sym #=> :cat
diff --git a/src/symbol.c b/src/symbol.c
index f550505d8..55799e266 100644
--- a/src/symbol.c
+++ b/src/symbol.c
@@ -389,12 +389,11 @@ mrb_init_symtbl(mrb_state *mrb)
/* 15.2.11.3.3 */
/*
* call-seq:
- * sym.id2name -> string
- * sym.to_s -> string
+ * sym.to_s -> string
*
* Returns the name or string corresponding to sym.
*
- * :fred.id2name #=> "fred"
+ * :fred.to_s #=> "fred"
*/
static mrb_value
sym_to_s(mrb_state *mrb, mrb_value sym)