diff --git a/proc.c b/proc.c
index 390b1bf3fa..0b1be9c212 100644
--- a/proc.c
+++ b/proc.c
@@ -2812,7 +2812,8 @@ method_inspect(VALUE method)
     TypedData_Get_Struct(method, struct METHOD, &method_data_type, data);
     str = rb_sprintf("#<% "PRIsVALUE": ", rb_obj_class(method));
 
-    mklass = data->klass;
+    mklass = data->iclass;
+    if (!mklass) mklass = data->klass;
 
     if (RB_TYPE_P(mklass, T_ICLASS)) {
         /* TODO: I'm not sure why mklass is T_ICLASS.
@@ -2852,6 +2853,12 @@ method_inspect(VALUE method)
 	}
     }
     else {
+        mklass = data->klass;
+        if (FL_TEST(mklass, FL_SINGLETON)) {
+            do {
+               mklass = RCLASS_SUPER(mklass);
+            } while (RB_TYPE_P(mklass, T_ICLASS));
+        }
 	rb_str_buf_append(str, rb_inspect(mklass));
 	if (defined_class != mklass) {
 	    rb_str_catf(str, "(% "PRIsVALUE")", defined_class);
diff --git a/spec/ruby/core/method/shared/to_s.rb b/spec/ruby/core/method/shared/to_s.rb
index 373398a785..7666322936 100644
--- a/spec/ruby/core/method/shared/to_s.rb
+++ b/spec/ruby/core/method/shared/to_s.rb
@@ -31,4 +31,22 @@ describe :method_to_s, shared: true do
   it "returns a String containing the Module the method is referenced from" do
     @string.should =~ /MethodSpecs::MySub/
   end
+
+  ruby_version_is '2.8' do
+    it "returns a String containing the Module containing the method if object has a singleton class but method is not defined in the singleton class" do
+      obj = MethodSpecs::MySub.new
+      obj.singleton_class
+      @m = obj.method(:bar)
+      @string = @m.send(@method).sub(/0x\w+/, '0xXXXXXX')
+      @string.should =~ /\A#<Method: MethodSpecs::MySub\(MethodSpecs::MyMod\)#bar\(\) /
+    end
+  end
+
+  it "returns a String containing the singleton class if method is defined in the singleton class" do
+    obj = MethodSpecs::MySub.new
+    def obj.bar; end
+    @m = obj.method(:bar)
+    @string = @m.send(@method).sub(/0x\w+/, '0xXXXXXX')
+    @string.should =~ /\A#<Method: #<MethodSpecs::MySub:0xXXXXXX>\.bar/
+  end
 end
diff --git a/test/ruby/test_method.rb b/test/ruby/test_method.rb
index 563011a03f..01a69059e8 100644
--- a/test/ruby/test_method.rb
+++ b/test/ruby/test_method.rb
@@ -465,6 +465,14 @@ class TestMethod < Test::Unit::TestCase
     c3.class_eval { alias bar foo }
     m3 = c3.new.method(:bar)
     assert_equal("#<Method: #{c3.inspect}(#{c.inspect})#bar(foo)() #{__FILE__}:#{line_no}>", m3.inspect, bug7806)
+
+    bug15608 = '[ruby-core:91570] [Bug #15608]'
+    c4 = Class.new(c)
+    c4.class_eval { alias bar foo }
+    o = c4.new
+    o.singleton_class
+    m4 = o.method(:bar)
+    assert_equal("#<Method: #{c4.inspect}(#{c.inspect})#bar(foo)() #{__FILE__}:#{line_no}>", m4.inspect, bug15608)
   end
 
   def test_callee_top_level