diff --git a/object.c b/object.c
index aaa3326ebf..ed7e0ff224 100644
--- a/object.c
+++ b/object.c
@@ -162,7 +162,7 @@ rb_obj_setup(VALUE obj, VALUE klass, VALUE type)
*
* Returns +true+ or +false+.
*
- * Like Object#==, if +object+ is an instance of Object
+ * Like Object#==, if +other+ is an instance of \Object
* (and not an instance of one of its many subclasses).
*
* This method is commonly overridden by those subclasses,
@@ -1892,11 +1892,12 @@ rb_mod_freeze(VALUE mod)
/*
* call-seq:
- * mod === obj -> true or false
+ * self === other -> true or false
*
- * Case Equality---Returns true if obj is an
- * instance of mod or an instance of one of mod's descendants.
- * Of limited use for modules, but can be used in case statements
+ * Returns whether +other+ is an instance of +self+,
+ * or is an instance of a subclass of +self+.
+ *
+ * Of limited use for modules, but can be used in +case+ statements
* to classify objects by class.
*/
diff --git a/range.c b/range.c
index 7aa917bc06..c8a4b9938b 100644
--- a/range.c
+++ b/range.c
@@ -2054,10 +2054,9 @@ VALUE rb_str_include_range_p(VALUE beg, VALUE end, VALUE val, VALUE exclusive);
/*
* call-seq:
- * self === object -> true or false
+ * self === other -> true or false
*
- * Returns +true+ if +object+ is between self.begin and self.end.
- * +false+ otherwise:
+ * Returns whether +other+ is between self.begin and self.end:
*
* (1..4) === 2 # => true
* (1..4) === 5 # => false
diff --git a/re.c b/re.c
index 621af13cd7..f8672d1d7c 100644
--- a/re.c
+++ b/re.c
@@ -3728,9 +3728,9 @@ rb_reg_match(VALUE re, VALUE str)
/*
* call-seq:
- * regexp === string -> true or false
+ * self === other -> true or false
*
- * Returns +true+ if +self+ finds a match in +string+:
+ * Returns whether +self+ finds a match in +other+:
*
* /^[a-z]*$/ === 'HELLO' # => false
* /^[A-Z]*$/ === 'HELLO' # => true