diff --git a/ext/store/bigquery/resource_urn.go b/ext/store/bigquery/resource_urn.go
index d3e8b90674..3d5790fa9f 100644
--- a/ext/store/bigquery/resource_urn.go
+++ b/ext/store/bigquery/resource_urn.go
@@ -73,13 +73,14 @@ type ResourceURNWithUpstreamsList []*ResourceURNWithUpstreams
 
 func (rs ResourceURNWithUpstreamsList) FlattenUnique() []*ResourceURNWithUpstreams {
 	var output []*ResourceURNWithUpstreams
-	for _, u := range rs {
-		if u == nil {
+	for _, r := range rs {
+		if r == nil {
 			continue
 		}
-		nested := ResourceURNWithUpstreamsList(u.Upstreams).FlattenUnique()
-		u.Upstreams = nil
-		output = append(output, u)
+		newResource := *r
+		newResource.Upstreams = nil
+		nested := ResourceURNWithUpstreamsList(r.Upstreams).FlattenUnique()
+		output = append(output, &newResource)
 		output = append(output, nested...)
 	}
 
@@ -88,13 +89,15 @@ func (rs ResourceURNWithUpstreamsList) FlattenUnique() []*ResourceURNWithUpstrea
 
 func (rs ResourceURNWithUpstreamsList) unique() ResourceURNWithUpstreamsList {
 	mapUnique := map[ResourceURN]*ResourceURNWithUpstreams{}
-	for _, u := range rs {
-		mapUnique[u.ResourceURN] = u
+	for _, r := range rs {
+		mapUnique[r.ResourceURN] = r
 	}
 
-	var output []*ResourceURNWithUpstreams
+	output := make([]*ResourceURNWithUpstreams, len(mapUnique))
+	i := 0
 	for _, u := range mapUnique {
-		output = append(output, u)
+		output[i] = u
+		i++
 	}
 	return output
 }
diff --git a/ext/store/bigquery/resource_urn_test.go b/ext/store/bigquery/resource_urn_test.go
index 369d3a1684..6fd6424e09 100644
--- a/ext/store/bigquery/resource_urn_test.go
+++ b/ext/store/bigquery/resource_urn_test.go
@@ -39,3 +39,52 @@ func TestURN(t *testing.T) {
 		assert.Equal(t, "bigquery://project:dataset.table", resourceURN.URN())
 	})
 }
+
+func TestFlattenUnique(t *testing.T) {
+	t.Run("should return flattened upstream in the form of resource", func(t *testing.T) {
+		resources := []*bigquery.ResourceURNWithUpstreams{
+			{
+				ResourceURN: newResourceURN("project_test_1", "dataset_test_1", "name_test_1"),
+			},
+			{
+				ResourceURN: newResourceURN("project_test_2", "dataset_test_2", "name_test_2"),
+				Upstreams: []*bigquery.ResourceURNWithUpstreams{
+					{
+						ResourceURN: newResourceURN("project_test_3", "dataset_test_3", "name_test_3"),
+					},
+					{
+						ResourceURN: newResourceURN("project_test_4", "dataset_test_4", "name_test_4"),
+					},
+					{
+						ResourceURN: newResourceURN("project_test_1", "dataset_test_1", "name_test_1"),
+					},
+					nil,
+				},
+			},
+		}
+
+		expectedResources := []*bigquery.ResourceURNWithUpstreams{
+			{
+				ResourceURN: newResourceURN("project_test_1", "dataset_test_1", "name_test_1"),
+			},
+			{
+				ResourceURN: newResourceURN("project_test_2", "dataset_test_2", "name_test_2"),
+			},
+			{
+				ResourceURN: newResourceURN("project_test_3", "dataset_test_3", "name_test_3"),
+			},
+			{
+				ResourceURN: newResourceURN("project_test_4", "dataset_test_4", "name_test_4"),
+			},
+		}
+
+		actualResources := bigquery.ResourceURNWithUpstreamsList(resources).FlattenUnique()
+
+		assert.ElementsMatch(t, expectedResources, actualResources)
+	})
+}
+
+func newResourceURN(project, dataset, name string) bigquery.ResourceURN {
+	resourceURN, _ := bigquery.NewResourceURN(project, dataset, name)
+	return resourceURN
+}