diff --git a/aws/data_source_aws_vpn_gateway.go b/aws/data_source_aws_vpn_gateway.go
index bffbe01305b..2d0fa3277ac 100644
--- a/aws/data_source_aws_vpn_gateway.go
+++ b/aws/data_source_aws_vpn_gateway.go
@@ -36,7 +36,7 @@ func dataSourceAwsVpnGateway() *schema.Resource {
 				Computed: true,
 			},
 			"amazon_side_asn": {
-				Type:     schema.TypeFloat,
+				Type:     schema.TypeString,
 				Optional: true,
 				Computed: true,
 			},
@@ -64,7 +64,7 @@ func dataSourceAwsVpnGatewayRead(d *schema.ResourceData, meta interface{}) error
 	if asn, ok := d.GetOk("amazon_side_asn"); ok {
 		req.Filters = append(req.Filters, buildEC2AttributeFilterList(
 			map[string]string{
-				"amazon-side-asn": strconv.FormatInt(int64(asn.(float64)), 10),
+				"amazon-side-asn": asn.(string),
 			},
 		)...)
 	}
@@ -104,7 +104,7 @@ func dataSourceAwsVpnGatewayRead(d *schema.ResourceData, meta interface{}) error
 	d.SetId(aws.StringValue(vgw.VpnGatewayId))
 	d.Set("state", vgw.State)
 	d.Set("availability_zone", vgw.AvailabilityZone)
-	d.Set("amazon_side_asn", float64(aws.Int64Value(vgw.AmazonSideAsn)))
+	d.Set("amazon_side_asn", strconv.FormatInt(aws.Int64Value(vgw.AmazonSideAsn), 10))
 	d.Set("tags", tagsToMap(vgw.Tags))
 
 	for _, attachment := range vgw.VpcAttachments {
diff --git a/aws/data_source_aws_vpn_gateway_test.go b/aws/data_source_aws_vpn_gateway_test.go
index 6c8e0b672cf..084060675e4 100644
--- a/aws/data_source_aws_vpn_gateway_test.go
+++ b/aws/data_source_aws_vpn_gateway_test.go
@@ -31,7 +31,7 @@ func TestAccDataSourceAwsVpnGateway_unattached(t *testing.T) {
 					resource.TestCheckResourceAttrSet("data.aws_vpn_gateway.test_by_id", "state"),
 					resource.TestCheckResourceAttr("data.aws_vpn_gateway.test_by_tags", "tags.%", "3"),
 					resource.TestCheckNoResourceAttr("data.aws_vpn_gateway.test_by_id", "attached_vpc_id"),
-					resource.TestCheckResourceAttr("data.aws_vpn_gateway.test_by_amazon_side_asn", "amazon_side_asn", "4.294967293E+09"),
+					resource.TestCheckResourceAttr("data.aws_vpn_gateway.test_by_amazon_side_asn", "amazon_side_asn", "4294967293"),
 				),
 			},
 		},
diff --git a/aws/resource_aws_vpn_gateway.go b/aws/resource_aws_vpn_gateway.go
index 2e95b5a17a7..57ed8a58605 100644
--- a/aws/resource_aws_vpn_gateway.go
+++ b/aws/resource_aws_vpn_gateway.go
@@ -3,6 +3,7 @@ package aws
 import (
 	"fmt"
 	"log"
+	"strconv"
 	"time"
 
 	"github.com/aws/aws-sdk-go/aws"
@@ -30,7 +31,7 @@ func resourceAwsVpnGateway() *schema.Resource {
 			},
 
 			"amazon_side_asn": {
-				Type:         schema.TypeFloat,
+				Type:         schema.TypeString,
 				Optional:     true,
 				ForceNew:     true,
 				Computed:     true,
@@ -56,7 +57,11 @@ func resourceAwsVpnGatewayCreate(d *schema.ResourceData, meta interface{}) error
 		Type:             aws.String("ipsec.1"),
 	}
 	if asn, ok := d.GetOk("amazon_side_asn"); ok {
-		createOpts.AmazonSideAsn = aws.Int64(int64(asn.(float64)))
+		i, err := strconv.ParseInt(asn.(string), 10, 64)
+		if err != nil {
+			return err
+		}
+		createOpts.AmazonSideAsn = aws.Int64(i)
 	}
 
 	// Create the VPN gateway
@@ -109,7 +114,7 @@ func resourceAwsVpnGatewayRead(d *schema.ResourceData, meta interface{}) error {
 	if vpnGateway.AvailabilityZone != nil && *vpnGateway.AvailabilityZone != "" {
 		d.Set("availability_zone", vpnGateway.AvailabilityZone)
 	}
-	d.Set("amazon_side_asn", float64(aws.Int64Value(vpnGateway.AmazonSideAsn)))
+	d.Set("amazon_side_asn", strconv.FormatInt(aws.Int64Value(vpnGateway.AmazonSideAsn), 10))
 	d.Set("tags", tagsToMap(vpnGateway.Tags))
 
 	return nil
diff --git a/aws/resource_aws_vpn_gateway_test.go b/aws/resource_aws_vpn_gateway_test.go
index 66e09d86aa9..481f76966be 100644
--- a/aws/resource_aws_vpn_gateway_test.go
+++ b/aws/resource_aws_vpn_gateway_test.go
@@ -140,7 +140,7 @@ func TestAccAWSVpnGateway_withAmazonSideAsnSetToState(t *testing.T) {
 				Check: resource.ComposeTestCheckFunc(
 					testAccCheckVpnGatewayExists("aws_vpn_gateway.foo", &v),
 					resource.TestCheckResourceAttr(
-						"aws_vpn_gateway.foo", "amazon_side_asn", "4.294967294E+09"),
+						"aws_vpn_gateway.foo", "amazon_side_asn", "4294967294"),
 				),
 			},
 		},
diff --git a/aws/validators.go b/aws/validators.go
index d4d4d685df8..990f90b36a8 100644
--- a/aws/validators.go
+++ b/aws/validators.go
@@ -6,6 +6,7 @@ import (
 	"net"
 	"net/url"
 	"regexp"
+	"strconv"
 	"strings"
 	"time"
 
@@ -2256,10 +2257,14 @@ func validateStringIn(validValues ...string) schema.SchemaValidateFunc {
 }
 
 func validateAmazonSideAsn(v interface{}, k string) (ws []string, errors []error) {
-	value := v.(float64)
+	value := v.(string)
 
 	// http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateVpnGateway.html
-	asn := int64(value)
+	asn, err := strconv.ParseInt(value, 10, 64)
+	if err != nil {
+		errors = append(errors, fmt.Errorf("%q (%q) must be a 64-bit integer", k, v))
+		return
+	}
 
 	if (asn < 64512) || (asn > 65534 && asn < 4200000000) || (asn > 4294967294) {
 		errors = append(errors, fmt.Errorf("%q (%q) must be in the range 64512 to 65534 or 4200000000 to 4294967294", k, v))
diff --git a/aws/validators_test.go b/aws/validators_test.go
index 05b8fffcf80..80e76312a61 100644
--- a/aws/validators_test.go
+++ b/aws/validators_test.go
@@ -3070,15 +3070,15 @@ func TestValidateGuardDutyThreatIntelSetFormat(t *testing.T) {
 }
 
 func TestValidateAmazonSideAsn(t *testing.T) {
-	validAsns := []float64{
-		64512,
-		64513,
-		65533,
-		65534,
-		4200000000,
-		4200000001,
-		4294967293,
-		4294967294,
+	validAsns := []string{
+		"64512",
+		"64513",
+		"65533",
+		"65534",
+		"4200000000",
+		"4200000001",
+		"4294967293",
+		"4294967294",
 	}
 	for _, v := range validAsns {
 		_, errors := validateAmazonSideAsn(v, "amazon_side_asn")
@@ -3087,8 +3087,10 @@ func TestValidateAmazonSideAsn(t *testing.T) {
 		}
 	}
 
-	invalidAsns := []float64{
-		1,
+	invalidAsns := []string{
+		"1",
+		"ABCDEFG",
+		"",
 	}
 	for _, v := range invalidAsns {
 		_, errors := validateAmazonSideAsn(v, "amazon_side_asn")