diff --git a/lib/matchers/document/be_stored_in.rb b/lib/matchers/document/be_stored_in.rb
index 2553f1f..ffd614d 100644
--- a/lib/matchers/document/be_stored_in.rb
+++ b/lib/matchers/document/be_stored_in.rb
@@ -17,6 +17,14 @@ def matches? subject
         class_of(subject).collection_name.to_s == collection_name
       end
 
+      def failure_message
+        "Expected #{inspect} to #{description}"
+      end
+
+      def negative_failure_message
+        "Expected not to #{description}"
+      end
+
       def description
         "be stored in #{collection_name.inspect}"
       end
diff --git a/lib/matchers/document/document.rb b/lib/matchers/document/document.rb
index 2f22fbc..511a67d 100644
--- a/lib/matchers/document/document.rb
+++ b/lib/matchers/document/document.rb
@@ -41,6 +41,14 @@ def matches? subject
           class_of(subject).included_modules.include? mod
         end
 
+        def failure_message
+          "Expected #{inspect} to #{description}"
+        end
+
+        def negative_failure_message
+          "Expected not to #{description}"
+        end
+
         def description
           msg = case
                 when mod == DOCUMENT   then ''
diff --git a/lib/matchers/document/have_field.rb b/lib/matchers/document/have_field.rb
index 806505b..4bc568f 100644
--- a/lib/matchers/document/have_field.rb
+++ b/lib/matchers/document/have_field.rb
@@ -14,6 +14,7 @@ class HaveFieldMatcher < Matcher
 
         def initialize *fields
           @fields = fields.collect(&:to_s)
+          @errors = []
         end
 
         def of_type type
@@ -27,8 +28,7 @@ def with_default_value default
         end
 
         def matches? subject
-          @klass  = class_of subject
-          @errors = []
+          @klass = class_of subject
 
           fields.each do |field|
             if klass.fields.include? field
diff --git a/lib/matchers/document/have_index.rb b/lib/matchers/document/have_index.rb
index 7ede086..4b1b835 100644
--- a/lib/matchers/document/have_index.rb
+++ b/lib/matchers/document/have_index.rb
@@ -16,7 +16,7 @@ def initialize *attrs
 
       def matches? subject
         @klass = class_of subject
-        klass.index_options.any? { |idx, _| idx.keys == @attrs }
+        klass.index_options.any? { |idx, _| idx.keys == attrs }
       end
 
       def failure_message
diff --git a/lib/matchers/matcher.rb b/lib/matchers/matcher.rb
index 3a0764f..65d5037 100644
--- a/lib/matchers/matcher.rb
+++ b/lib/matchers/matcher.rb
@@ -2,14 +2,6 @@ module Mongoid
   module Matchers
     class Matcher
       include MiniTest::Matchers::ActiveModel::Helpers
-
-      def failure_message
-        "Expected #{inspect} to #{description}".squeeze ' '
-      end
-
-      def negative_failure_message
-        "Expected not to #{description}".squeeze ' '
-      end
     end
   end
 end