diff --git a/google/resource_bigquery_data_transfer_config.go b/google/resource_bigquery_data_transfer_config.go
index 87ea57602a4..c1600f02fc3 100644
--- a/google/resource_bigquery_data_transfer_config.go
+++ b/google/resource_bigquery_data_transfer_config.go
@@ -379,7 +379,17 @@ func flattenBigqueryDataTransferConfigDisabled(v interface{}, d *schema.Resource
 }
 
 func flattenBigqueryDataTransferConfigParams(v interface{}, d *schema.ResourceData) interface{} {
-	return v
+	if v == nil {
+		return v
+	}
+
+	kv := v.(map[string]interface{})
+
+	res := make(map[string]string)
+	for key, value := range kv {
+		res[key] = fmt.Sprintf("%v", value)
+	}
+	return res
 }
 
 func expandBigqueryDataTransferConfigDisplayName(v interface{}, d TerraformResourceData, config *Config) (interface{}, error) {
diff --git a/google/resource_bigquery_data_transfer_config_test.go b/google/resource_bigquery_data_transfer_config_test.go
index 5640b9eceb1..8d4c31e0549 100644
--- a/google/resource_bigquery_data_transfer_config_test.go
+++ b/google/resource_bigquery_data_transfer_config_test.go
@@ -14,8 +14,9 @@ import (
 // but it will get deleted by parallel tests, so they need to be ran serially.
 func TestAccBigqueryDataTransferConfig(t *testing.T) {
 	testCases := map[string]func(t *testing.T){
-		"basic":  testAccBigqueryDataTransferConfig_scheduledQuery_basic,
-		"update": testAccBigqueryDataTransferConfig_scheduledQuery_update,
+		"basic":        testAccBigqueryDataTransferConfig_scheduledQuery_basic,
+		"update":       testAccBigqueryDataTransferConfig_scheduledQuery_update,
+		"booleanParam": testAccBigqueryDataTransferConfig_copy_booleanParam,
 	}
 
 	for name, tc := range testCases {
@@ -75,6 +76,27 @@ func testAccBigqueryDataTransferConfig_scheduledQuery_update(t *testing.T) {
 	})
 }
 
+func testAccBigqueryDataTransferConfig_copy_booleanParam(t *testing.T) {
+	random_suffix := acctest.RandString(10)
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckBigqueryDataTransferConfigDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccBigqueryDataTransferConfig_booleanParam(random_suffix),
+			},
+			{
+				ResourceName:            "google_bigquery_data_transfer_config.copy_config",
+				ImportState:             true,
+				ImportStateVerify:       true,
+				ImportStateVerifyIgnore: []string{"location"},
+			},
+		},
+	})
+}
+
 func testAccCheckBigqueryDataTransferConfigDestroy(s *terraform.State) error {
 	for name, rs := range s.RootModule().Resources {
 		if rs.Type != "google_bigquery_data_transfer_config" {
@@ -135,3 +157,47 @@ resource "google_bigquery_data_transfer_config" "query_config" {
 }
 `, random_suffix, random_suffix, schedule, letter)
 }
+
+func testAccBigqueryDataTransferConfig_booleanParam(random_suffix string) string {
+	return fmt.Sprintf(`
+data "google_project" "project" {}
+
+resource "google_project_iam_member" "permissions" {
+  role = "roles/iam.serviceAccountShortTermTokenMinter"
+  member = "serviceAccount:service-${data.google_project.project.number}@gcp-sa-bigquerydatatransfer.iam.gserviceaccount.com"
+}
+
+resource "google_bigquery_dataset" "source_dataset" {
+  depends_on = [google_project_iam_member.permissions]
+
+  dataset_id = "source_%s"
+  friendly_name = "foo"
+  description = "bar"
+  location = "asia-northeast1"
+}
+
+resource "google_bigquery_dataset" "destination_dataset" {
+  depends_on = [google_project_iam_member.permissions]
+
+  dataset_id = "destination_%s"
+  friendly_name = "foo"
+  description = "bar"
+  location = "asia-northeast1"
+}
+
+resource "google_bigquery_data_transfer_config" "copy_config" {
+  depends_on = [google_project_iam_member.permissions]
+
+  location = "asia-northeast1"
+
+  display_name = "Copy test %s"
+  data_source_id = "cross_region_copy"
+  destination_dataset_id = google_bigquery_dataset.destination_dataset.dataset_id
+  params = {
+    overwrite_destination_table = "true"
+    source_dataset_id = google_bigquery_dataset.source_dataset.dataset_id
+    source_project_id = data.google_project.project.project_id
+  }
+}
+`, random_suffix, random_suffix, random_suffix)
+}