diff --git a/aws/resource_aws_service_discovery_public_dns_namespace.go b/aws/resource_aws_service_discovery_public_dns_namespace.go
index e112dfaf4e9d..d311f2247d97 100644
--- a/aws/resource_aws_service_discovery_public_dns_namespace.go
+++ b/aws/resource_aws_service_discovery_public_dns_namespace.go
@@ -1,7 +1,6 @@
 package aws
 
 import (
-	"fmt"
 	"time"
 
 	"github.com/aws/aws-sdk-go/aws"
@@ -46,9 +45,17 @@ func resourceAwsServiceDiscoveryPublicDnsNamespace() *schema.Resource {
 func resourceAwsServiceDiscoveryPublicDnsNamespaceCreate(d *schema.ResourceData, meta interface{}) error {
 	conn := meta.(*AWSClient).sdconn
 
-	requestId := resource.PrefixedUniqueId(fmt.Sprintf("tf-%s", d.Get("name").(string)))
+	name := d.Get("name").(string)
+	// The CreatorRequestId has a limit of 64 bytes
+	var requestId string
+	if len(name) > (64 - resource.UniqueIDSuffixLength) {
+		requestId = resource.PrefixedUniqueId(name[0:(64 - resource.UniqueIDSuffixLength - 1)])
+	} else {
+		requestId = resource.PrefixedUniqueId(name)
+	}
+
 	input := &servicediscovery.CreatePublicDnsNamespaceInput{
-		Name:             aws.String(d.Get("name").(string)),
+		Name:             aws.String(name),
 		CreatorRequestId: aws.String(requestId),
 	}
 
diff --git a/aws/resource_aws_service_discovery_public_dns_namespace_test.go b/aws/resource_aws_service_discovery_public_dns_namespace_test.go
index f082c4b9fb36..ecaa3834a4e4 100644
--- a/aws/resource_aws_service_discovery_public_dns_namespace_test.go
+++ b/aws/resource_aws_service_discovery_public_dns_namespace_test.go
@@ -95,6 +95,26 @@ func testAccCheckAwsServiceDiscoveryPublicDnsNamespaceExists(name string) resour
 	}
 }
 
+func testAccAWSServiceDiscoveryPublicDnsNamespace_longname(t *testing.T) {
+	rName := acctest.RandString(64 - len("terraform.com"))
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckAwsServiceDiscoveryPublicDnsNamespaceDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccServiceDiscoveryPublicDnsNamespaceConfig(rName),
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckAwsServiceDiscoveryPublicDnsNamespaceExists("aws_service_discovery_public_dns_namespace.test"),
+					resource.TestCheckResourceAttrSet("aws_service_discovery_public_dns_namespace.test", "arn"),
+					resource.TestCheckResourceAttrSet("aws_service_discovery_public_dns_namespace.test", "hosted_zone"),
+				),
+			},
+		},
+	})
+}
+
 func testAccServiceDiscoveryPublicDnsNamespaceConfig(rName string) string {
 	return fmt.Sprintf(`
 resource "aws_service_discovery_public_dns_namespace" "test" {