diff --git a/builder/amazon/common/run_config.go b/builder/amazon/common/run_config.go
index 729ebce13..fa648dc96 100644
--- a/builder/amazon/common/run_config.go
+++ b/builder/amazon/common/run_config.go
@@ -44,10 +44,14 @@ type RunConfig struct {
 }
 
 func (c *RunConfig) Prepare(ctx *interpolate.Context) []error {
-	// if we are not given an explicit keypairname, create a temporary one
+	// If we are not given an explicit ssh_keypair_name,
+	// then create a temporary one, but only if the
+	// temporary_key_pair_name has not been provided.
 	if c.SSHKeyPairName == "" {
-		c.TemporaryKeyPairName = fmt.Sprintf(
-			"packer %s", uuid.TimeOrderedUUID())
+		if c.TemporaryKeyPairName == "" {
+			c.TemporaryKeyPairName = fmt.Sprintf(
+				"packer_%s", uuid.TimeOrderedUUID())
+		}
 	}
 
 	if c.WindowsPasswordTimeout == 0 {
diff --git a/builder/amazon/common/run_config_test.go b/builder/amazon/common/run_config_test.go
index 0b029169b..7f307e288 100644
--- a/builder/amazon/common/run_config_test.go
+++ b/builder/amazon/common/run_config_test.go
@@ -3,6 +3,7 @@ package common
 import (
 	"io/ioutil"
 	"os"
+	"regexp"
 	"testing"
 
 	"github.com/mitchellh/packer/helper/communicator"
@@ -140,6 +141,21 @@ func TestRunConfigPrepare_TemporaryKeyPairName(t *testing.T) {
 	}
 
 	if c.TemporaryKeyPairName == "" {
-		t.Fatal("keypair empty")
+		t.Fatal("keypair name is empty")
+	}
+
+	// Match prefix and UUID, e.g. "packer_5790d491-a0b8-c84c-c9d2-2aea55086550".
+	r := regexp.MustCompile(`\Apacker_(?:(?i)[a-f\d]{8}(?:-[a-f\d]{4}){3}-[a-f\d]{12}?)\z`)
+	if !r.MatchString(c.TemporaryKeyPairName) {
+		t.Fatal("keypair name is not valid")
+	}
+
+	c.TemporaryKeyPairName = "ssh-key-123"
+	if err := c.Prepare(nil); len(err) != 0 {
+		t.Fatalf("err: %s", err)
+	}
+
+	if c.TemporaryKeyPairName != "ssh-key-123" {
+		t.Fatal("keypair name does not match")
 	}
 }
diff --git a/builder/amazon/common/step_run_source_instance.go b/builder/amazon/common/step_run_source_instance.go
index 6eeb59604..abd9a5d50 100644
--- a/builder/amazon/common/step_run_source_instance.go
+++ b/builder/amazon/common/step_run_source_instance.go
@@ -156,16 +156,16 @@ func (s *StepRunSourceInstance) Run(state multistep.StateBag) multistep.StepActi
 
 	if spotPrice == "" || spotPrice == "0" {
 		runOpts := &ec2.RunInstancesInput{
-			KeyName:                           &keyName,
-			ImageId:                           &s.SourceAMI,
-			InstanceType:                      &s.InstanceType,
-			UserData:                          &userData,
-			MaxCount:                          aws.Int64(1),
-			MinCount:                          aws.Int64(1),
-			IamInstanceProfile:                &ec2.IamInstanceProfileSpecification{Name: &s.IamInstanceProfile},
-			BlockDeviceMappings:               s.BlockDevices.BuildLaunchDevices(),
-			Placement:                         &ec2.Placement{AvailabilityZone: &s.AvailabilityZone},
-			EbsOptimized:                      &s.EbsOptimized,
+			KeyName:             &keyName,
+			ImageId:             &s.SourceAMI,
+			InstanceType:        &s.InstanceType,
+			UserData:            &userData,
+			MaxCount:            aws.Int64(1),
+			MinCount:            aws.Int64(1),
+			IamInstanceProfile:  &ec2.IamInstanceProfileSpecification{Name: &s.IamInstanceProfile},
+			BlockDeviceMappings: s.BlockDevices.BuildLaunchDevices(),
+			Placement:           &ec2.Placement{AvailabilityZone: &s.AvailabilityZone},
+			EbsOptimized:        &s.EbsOptimized,
 		}
 
 		if s.SubnetId != "" && s.AssociatePublicIpAddress {
diff --git a/builder/amazon/ebs/builder.go b/builder/amazon/ebs/builder.go
index 638efa5a3..7174d6b8e 100644
--- a/builder/amazon/ebs/builder.go
+++ b/builder/amazon/ebs/builder.go
@@ -117,21 +117,21 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			BlockDevices: b.config.BlockDevices,
 		},
 		&awscommon.StepRunSourceInstance{
-			Debug:                             b.config.PackerDebug,
-			ExpectedRootDevice:                "ebs",
-			SpotPrice:                         b.config.SpotPrice,
-			SpotPriceProduct:                  b.config.SpotPriceAutoProduct,
-			InstanceType:                      b.config.InstanceType,
-			UserData:                          b.config.UserData,
-			UserDataFile:                      b.config.UserDataFile,
-			SourceAMI:                         b.config.SourceAmi,
-			IamInstanceProfile:                b.config.IamInstanceProfile,
-			SubnetId:                          b.config.SubnetId,
-			AssociatePublicIpAddress:          b.config.AssociatePublicIpAddress,
-			EbsOptimized:                      b.config.EbsOptimized,
-			AvailabilityZone:                  b.config.AvailabilityZone,
-			BlockDevices:                      b.config.BlockDevices,
-			Tags:                              b.config.RunTags,
+			Debug:                    b.config.PackerDebug,
+			ExpectedRootDevice:       "ebs",
+			SpotPrice:                b.config.SpotPrice,
+			SpotPriceProduct:         b.config.SpotPriceAutoProduct,
+			InstanceType:             b.config.InstanceType,
+			UserData:                 b.config.UserData,
+			UserDataFile:             b.config.UserDataFile,
+			SourceAMI:                b.config.SourceAmi,
+			IamInstanceProfile:       b.config.IamInstanceProfile,
+			SubnetId:                 b.config.SubnetId,
+			AssociatePublicIpAddress: b.config.AssociatePublicIpAddress,
+			EbsOptimized:             b.config.EbsOptimized,
+			AvailabilityZone:         b.config.AvailabilityZone,
+			BlockDevices:             b.config.BlockDevices,
+			Tags:                     b.config.RunTags,
 			InstanceInitiatedShutdownBehavior: b.config.InstanceInitiatedShutdownBehavior,
 		},
 		&stepTagEBSVolumes{