diff --git a/lib/graphql/schema_comparator/diff/schema.rb b/lib/graphql/schema_comparator/diff/schema.rb
index 1e9043d..f99b763 100644
--- a/lib/graphql/schema_comparator/diff/schema.rb
+++ b/lib/graphql/schema_comparator/diff/schema.rb
@@ -17,8 +17,8 @@ def diff
           changes = []
 
           # Removed and Added Types
-          changes += removed_types.map { |type| Changes::TypeRemoved.new(type) }
-          changes += added_types.map { |type| Changes::TypeAdded.new(type) }
+          removed_types.each { |type| changes += changes_in_removed_type(type) }
+          added_types.each  { |type| changes += changes_in_added_type(type) }
 
           # Type Diff for common types
           each_common_type do |old_type, new_type|
@@ -34,6 +34,22 @@ def diff
           changes
         end
 
+        def changes_in_added_type(type)
+          changes = [Changes::TypeAdded.new(type)]
+          if type.graphql_definition.is_a?(GraphQL::ObjectType)
+            type.interfaces.each do |interface|
+              if old_types[interface.graphql_name]
+                changes << Changes::ObjectTypeInterfaceAdded.new(interface, type)
+              end
+            end
+          end
+          changes
+        end
+
+        def changes_in_removed_type(type)
+          [Changes::TypeRemoved.new(type)]
+        end
+
         def changes_in_type(old_type, new_type)
           changes = []
 
diff --git a/test/lib/graphql/schema_comparator/diff/schema_test.rb b/test/lib/graphql/schema_comparator/diff/schema_test.rb
index 83c23d2..ae23d12 100644
--- a/test/lib/graphql/schema_comparator/diff/schema_test.rb
+++ b/test/lib/graphql/schema_comparator/diff/schema_test.rb
@@ -109,6 +109,13 @@ def setup
       type WithInterfaces implements AnInterface {
         a: String!
       }
+      interface ANewInterface {
+        c: Int
+      }
+      type AnotherWithInterfaces implements AnInterface, ANewInterface {
+        interfaceField: Int!
+        c: Int
+      }
       type WithArguments {
         a(
           # Description for a
@@ -175,6 +182,9 @@ def test_changes_kitchensink
       "Field `b` was added to object type `AnotherInterface`",
       "`WithInterfaces` object type no longer implements `AnotherInterface` interface",
       "Field `anotherInterfaceField` was removed from object type `WithInterfaces`",
+      "Type `ANewInterface` was added",
+      "Type `AnotherWithInterfaces` was added",
+      "`AnotherWithInterfaces` object implements `AnInterface` interface",
       "Description for argument `a` on field `WithArguments.a` changed from `Meh` to `Description for a`",
       "Type for argument `b` on field `WithArguments.a` changed from `String` to `String!`",
       "Default value for argument `arg` on field `WithArguments.b` changed from `1` to `2`",
@@ -192,7 +202,7 @@ def test_changes_kitchensink
       "Argument `willBeRemoved` was removed from directive `yolo`",
       "Description for argument `someArg` on directive `yolo` changed from `Included when true.` to `someArg does stuff`",
       "Type for argument `someArg` on directive `yolo` changed from `Boolean!` to `String!`",
-    ].sort, @differ.diff.map(&:message).sort
+    ].sort.join("\n"), @differ.diff.map(&:message).sort.join("\n")
 
     assert_equal [
       "WillBeRemoved",
@@ -220,6 +230,9 @@ def test_changes_kitchensink
       "AnotherInterface.b",
       "WithInterfaces",
       "WithInterfaces.anotherInterfaceField",
+      "ANewInterface",
+      "AnotherWithInterfaces",
+      "AnotherWithInterfaces",
       "WithArguments.a.a",
       "WithArguments.a.b",
       "WithArguments.b.arg",
@@ -238,6 +251,6 @@ def test_changes_kitchensink
       "@yolo.someArg",
       "@yolo.someArg",
       "@yolo.anotherArg",
-    ].sort, @differ.diff.map(&:path).sort
+    ].sort.join("\n"), @differ.diff.map(&:path).sort.join("\n")
   end
 end