diff --git a/lib/method_source.rb b/lib/method_source.rb
index ffd79ad..8819efa 100644
--- a/lib/method_source.rb
+++ b/lib/method_source.rb
@@ -152,7 +152,7 @@ def class_comment
         class_inst_or_module = class_inst_or_module.class
       end
 
-      location = class_inst_or_module.const_source_location(const_name)
+      location = class_inst_or_module.const_source_location("::#{const_name}")
 
       MethodSource.comment_helper(location, defined?(name) ? name : inspect)
     end
diff --git a/spec/method_source_spec.rb b/spec/method_source_spec.rb
index 1927670..67898bf 100644
--- a/spec/method_source_spec.rb
+++ b/spec/method_source_spec.rb
@@ -1,5 +1,11 @@
 require 'spec_helper'
 
+# Documentation for the outer class.
+class MethodSourceShadowedClass
+  MethodSourceShadowedClass = Module.new
+  def work; end
+end
+
 describe MethodSource do
 
   describe "source_location (testing 1.8 implementation)" do
@@ -96,6 +102,11 @@
 
   # if RUBY_VERSION =~ /1.9/ || is_rbx?
   describe "Lambdas and Procs" do
+    it "uses the absolute class name when a nested constant shadows it" do
+      comment = MethodSourceShadowedClass.new.method(:work).class_comment
+      expect(comment).to eq("# Documentation for the outer class.\n")
+    end
+
     it 'should return source for proc' do
       expect(MyProc.source).to eq(@proc_source)
     end