diff --git a/merge.go b/merge.go
index 1f103073..edca49a4 100644
--- a/merge.go
+++ b/merge.go
@@ -59,7 +59,7 @@ func buildFieldURLMap(services ...*Service) FieldURLMap {
 	result := FieldURLMap{}
 	for _, rs := range services {
 		for _, t := range rs.Schema.Types {
-			if t.Kind != ast.Object || isGraphQLBuiltinName(t.Name) || t.Name == serviceObjectName {
+			if !t.IsCompositeType() || isGraphQLBuiltinName(t.Name) || t.Name == serviceObjectName {
 				continue
 			}
 			for _, f := range mergeableFields(t) {
diff --git a/merge_test.go b/merge_test.go
index 3d1743ae..2ec68db1 100644
--- a/merge_test.go
+++ b/merge_test.go
@@ -448,6 +448,7 @@ func TestBuildFieldURLMapSingleSchema(t *testing.T) {
 		Location1: loc1,
 		Expected: FieldURLMap{
 			"Query.gizmo": loc1,
+			"Named.name":  loc1,
 			"Gizmo.id":    loc1,
 			"Gizmo.name":  loc1,
 		},
@@ -496,6 +497,8 @@ func TestBuildFieldURLMapTwoSchemasNoBoundaryType(t *testing.T) {
 			"Gizmo.name":    loc1,
 			"Gimmick.id":    loc2,
 			"Gimmick.size":  loc2,
+			"Named.name":    loc1,
+			"Sized.size":    loc2,
 		},
 	}
 	fixture.Check(t)
@@ -561,6 +564,9 @@ func TestBuildFieldURLMapTwoSchemasWithBoundaryType(t *testing.T) {
 			"Query.gizmo": loc1,
 			"Gizmo.name":  loc1,
 			"Gizmo.size":  loc2,
+			"Named.name":  loc1,
+			"Sized.size":  loc2,
+			"Node.id":     loc2,
 		},
 	}
 	fixture.Check(t)