diff --git a/ChangeLog b/ChangeLog
index 694edeb..c73d4ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jul  9 18:31:49 2015  Ferdinand Niedermann  <nerdinand@nerdinand.com>
+
+  * compar.c (cmp_clamp): Introduce Comparable#clamp [Bug #10594]
+
 Thu Jul  9 15:07:12 2015  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* win32/win32.c (waitpid): return immediately if interrupted.
diff --git a/compar.c b/compar.c
index 946d0e0..e33811e 100644
--- a/compar.c
+++ b/compar.c
@@ -173,6 +173,35 @@ cmp_between(VALUE x, VALUE min, VALUE max)
     return Qtrue;
 }
 
+
+/*
+ *  call-seq:
+ *     obj.clamp(min, max) ->  obj
+ *
+ * Returns <i>min</i> if <i>obj</i> <code><=></code> <i>min</i> is less
+ * than zero, <i>max</i> if <i>obj</i> <code><=></code> <i>min</i> is
+ * greater than zero and <i>obj</i> otherwise.
+ *
+ *     12.clamp(0, 100)         #=> 12
+ *     523.clamp(0, 100)        #=> 100
+ *     -3.123.clamp(0, 100)     #=> 0
+ *
+ *     'd'.clamp('a', 'f')      #=> 'd'
+ *     'z'.clamp('a', 'f')      #=> 'f'
+ */
+
+static VALUE
+cmp_clamp(VALUE x, VALUE min, VALUE max)
+{
+    if (RTEST(cmp_gt(min, max))) {
+        rb_raise(rb_eArgError, "min argument must be smaller than max argument");
+    }
+
+    if (RTEST(cmp_lt(x, min))) return min;
+    if (RTEST(cmp_gt(x, max))) return max;
+    return x;
+}
+
 /*
  *  The <code>Comparable</code> mixin is used by classes whose objects
  *  may be ordered. The class must define the <code><=></code> operator,
@@ -225,6 +254,7 @@ Init_Comparable(void)
     rb_define_method(rb_mComparable, "<", cmp_lt, 1);
     rb_define_method(rb_mComparable, "<=", cmp_le, 1);
     rb_define_method(rb_mComparable, "between?", cmp_between, 2);
+    rb_define_method(rb_mComparable, "clamp", cmp_clamp, 2);
 
     cmp = rb_intern("<=>");
 }
diff --git a/test/ruby/test_comparable.rb b/test/ruby/test_comparable.rb
index dab6be5..e40ae16 100644
--- a/test/ruby/test_comparable.rb
+++ b/test/ruby/test_comparable.rb
@@ -75,6 +75,20 @@ class TestComparable < Test::Unit::TestCase
     assert_equal(true, @o.between?(0, 0))
   end
 
+  def test_clamp
+    cmp->(x) do 0 <=> x end
+    assert_equal(1, @o.clamp(1, 2))
+    assert_equal(-1, @o.clamp(-2, -1))
+    assert_equal(0, @o.clamp(-1, 3))
+
+    assert_equal(1, @o.clamp(1, 1))
+    assert_equal(0, @o.clamp(0, 0))
+
+    assert_raise_with_message(ArgumentError, 'min argument must be smaller than max argument') {
+      @o.clamp(2, 1)
+    }
+   end
+
   def test_err
     assert_raise(ArgumentError) { 1.0 < nil }
     assert_raise(ArgumentError) { 1.0 < Object.new }