diff --git a/codegen/object.go b/codegen/object.go
index 70429a21ca7..7b9e3d6f597 100644
--- a/codegen/object.go
+++ b/codegen/object.go
@@ -84,8 +84,8 @@ type Objects []*Object
 
 func (o *Object) Implementors() string {
 	satisfiedBy := strconv.Quote(o.Name)
-	for _, s := range o.Definition.Interfaces {
-		satisfiedBy += ", " + strconv.Quote(s)
+	for _, s := range o.Implements {
+		satisfiedBy += ", " + strconv.Quote(s.Name)
 	}
 	return "[]string{" + satisfiedBy + "}"
 }
diff --git a/codegen/testserver/generated.go b/codegen/testserver/generated.go
index 8351189ad9c..a58e8e26b41 100644
--- a/codegen/testserver/generated.go
+++ b/codegen/testserver/generated.go
@@ -3657,7 +3657,7 @@ func (ec *executionContext) _ShapeUnion(ctx context.Context, sel ast.SelectionSe
 
 // region    **************************** object.gotpl ****************************
 
-var circleImplementors = []string{"Circle", "Shape"}
+var circleImplementors = []string{"Circle", "Shape", "ShapeUnion"}
 
 func (ec *executionContext) _Circle(ctx context.Context, sel ast.SelectionSet, obj *Circle) graphql.Marshaler {
 	fields := graphql.CollectFields(ctx, sel, circleImplementors)
@@ -4097,7 +4097,7 @@ func (ec *executionContext) _Query(ctx context.Context, sel ast.SelectionSet) gr
 	return out
 }
 
-var rectangleImplementors = []string{"Rectangle", "Shape"}
+var rectangleImplementors = []string{"Rectangle", "Shape", "ShapeUnion"}
 
 func (ec *executionContext) _Rectangle(ctx context.Context, sel ast.SelectionSet, obj *Rectangle) graphql.Marshaler {
 	fields := graphql.CollectFields(ctx, sel, rectangleImplementors)
diff --git a/example/starwars/generated.go b/example/starwars/generated.go
index eadab3d5563..e69ac3f814b 100644
--- a/example/starwars/generated.go
+++ b/example/starwars/generated.go
@@ -2897,7 +2897,7 @@ func (ec *executionContext) _SearchResult(ctx context.Context, sel ast.Selection
 
 // region    **************************** object.gotpl ****************************
 
-var droidImplementors = []string{"Droid", "Character"}
+var droidImplementors = []string{"Droid", "Character", "SearchResult"}
 
 func (ec *executionContext) _Droid(ctx context.Context, sel ast.SelectionSet, obj *Droid) graphql.Marshaler {
 	fields := graphql.CollectFields(ctx, sel, droidImplementors)
@@ -3024,7 +3024,7 @@ func (ec *executionContext) _FriendsEdge(ctx context.Context, sel ast.SelectionS
 	return out
 }
 
-var humanImplementors = []string{"Human", "Character"}
+var humanImplementors = []string{"Human", "Character", "SearchResult"}
 
 func (ec *executionContext) _Human(ctx context.Context, sel ast.SelectionSet, obj *Human) graphql.Marshaler {
 	fields := graphql.CollectFields(ctx, sel, humanImplementors)
@@ -3263,7 +3263,7 @@ func (ec *executionContext) _Review(ctx context.Context, sel ast.SelectionSet, o
 	return out
 }
 
-var starshipImplementors = []string{"Starship"}
+var starshipImplementors = []string{"Starship", "SearchResult"}
 
 func (ec *executionContext) _Starship(ctx context.Context, sel ast.SelectionSet, obj *Starship) graphql.Marshaler {
 	fields := graphql.CollectFields(ctx, sel, starshipImplementors)
diff --git a/example/type-system-extension/generated.go b/example/type-system-extension/generated.go
index 79575cf6e9b..190b4c6ba87 100644
--- a/example/type-system-extension/generated.go
+++ b/example/type-system-extension/generated.go
@@ -1613,7 +1613,7 @@ func (ec *executionContext) _MyQuery(ctx context.Context, sel ast.SelectionSet)
 	return out
 }
 
-var todoImplementors = []string{"Todo", "Node"}
+var todoImplementors = []string{"Todo", "Node", "Data"}
 
 func (ec *executionContext) _Todo(ctx context.Context, sel ast.SelectionSet, obj *Todo) graphql.Marshaler {
 	fields := graphql.CollectFields(ctx, sel, todoImplementors)