diff --git a/array.c b/array.c
index abf52634214af0..bac74e07cfbb92 100644
--- a/array.c
+++ b/array.c
@@ -5895,7 +5895,7 @@ rb_ary_union_hash(VALUE hash, VALUE ary2)
  *
  *  Returns the union of +self+ and +other_array+;
  *  duplicates are removed; order is preserved;
- *  items are compared using <tt>eql?</tt>:
+ *  items are compared using <tt>eql?</tt> and <tt>hash</tt>:
  *
  *    [0, 1] | [2, 3] # => [0, 1, 2, 3]
  *    [0, 1, 1] | [2, 2, 3] # => [0, 1, 2, 3]
@@ -5929,7 +5929,7 @@ rb_ary_or(VALUE ary1, VALUE ary2)
  *
  *  Returns a new array that is the union of the elements of +self+
  *  and all given arrays +other_arrays+;
- *  items are compared using <tt>eql?</tt>:
+ *  items are compared using <tt>eql?</tt> and <tt>hash</tt>:
  *
  *    [0, 1, 2, 3].union([4, 5], [6, 7]) # => [0, 1, 2, 3, 4, 5, 6, 7]
  *
@@ -6429,7 +6429,7 @@ push_value(st_data_t key, st_data_t val, st_data_t ary)
  *  returns +self+ if any elements removed, +nil+ otherwise.
  *
  *  With no block given, identifies and removes elements using method <tt>eql?</tt>
- *  to compare elements:
+ *  and <tt>hash</tt> to compare elements:
  *
  *    a = [0, 0, 1, 1, 2, 2]
  *    a.uniq! # => [0, 1, 2]
@@ -6437,7 +6437,7 @@ push_value(st_data_t key, st_data_t val, st_data_t ary)
  *
  *  With a block given, calls the block for each element;
  *  identifies and omits "duplicate" elements using method <tt>eql?</tt>
- *  to compare <i>block return values</i>;
+ *  and <tt>hash</tt> to compare <i>block return values</i>;
  *  that is, an element is a duplicate if its block return value
  *  is the same as that of a previous element:
  *
@@ -6486,14 +6486,14 @@ rb_ary_uniq_bang(VALUE ary)
  *  the first occurrence always being retained.
  *
  *  With no block given, identifies and omits duplicate elements using method <tt>eql?</tt>
- *  to compare elements:
+ *  and <tt>hash</tt> to compare elements:
  *
  *    a = [0, 0, 1, 1, 2, 2]
  *    a.uniq # => [0, 1, 2]
  *
  *  With a block given, calls the block for each element;
  *  identifies and omits "duplicate" elements using method <tt>eql?</tt>
- *  to compare <i>block return values</i>;
+ *  and <tt>hash</tt> to compare <i>block return values</i>;
  *  that is, an element is a duplicate if its block return value
  *  is the same as that of a previous element:
  *