diff --git a/lib/mocha/parameters_matcher.rb b/lib/mocha/parameters_matcher.rb
index 72645fe6..da1abb54 100644
--- a/lib/mocha/parameters_matcher.rb
+++ b/lib/mocha/parameters_matcher.rb
@@ -22,9 +22,13 @@ def parameters_match?(actual_parameters)
     end
 
     def mocha_inspect
-      signature = matchers.mocha_inspect
-      signature = signature.gsub(/^\[|\]$/, '')
-      "(#{signature})"
+      if @matching_block
+        '(arguments_accepted_by_custom_matching_block)'
+      else
+        signature = matchers.mocha_inspect
+        signature = signature.gsub(/^\[|\]$/, '')
+        "(#{signature})"
+      end
     end
 
     def matchers
diff --git a/test/unit/parameters_matcher_test.rb b/test/unit/parameters_matcher_test.rb
index 53ffafa7..a97d2d4a 100644
--- a/test/unit/parameters_matcher_test.rb
+++ b/test/unit/parameters_matcher_test.rb
@@ -103,4 +103,9 @@ def test_should_indicate_that_matcher_will_match_any_actual_parameters
     parameters_matcher = ParametersMatcher.new
     assert_equal '(any_parameters)', parameters_matcher.mocha_inspect
   end
+
+  def test_should_indicate_that_matcher_logic_is_defined_by_custom_block
+    parameters_matcher = ParametersMatcher.new { true }
+    assert_equal '(arguments_accepted_by_custom_matching_block)', parameters_matcher.mocha_inspect
+  end
 end