diff --git a/command/version.go b/command/version.go
index 4fb07a90f..85b61844b 100644
--- a/command/version.go
+++ b/command/version.go
@@ -40,7 +40,7 @@ func (c *VersionCommand) Run(args []string) int {
 	var versionString bytes.Buffer
 	fmt.Fprintf(&versionString, "Packer v%s", c.Version)
 	if c.VersionPrerelease != "" {
-		fmt.Fprintf(&versionString, ".%s", c.VersionPrerelease)
+		fmt.Fprintf(&versionString, "-%s", c.VersionPrerelease)
 
 		if c.Revision != "" {
 			fmt.Fprintf(&versionString, " (%s)", c.Revision)
diff --git a/version/version.go b/version/version.go
index 69a326a45..d5953c33f 100644
--- a/version/version.go
+++ b/version/version.go
@@ -20,7 +20,7 @@ func FormattedVersion() string {
 	var versionString bytes.Buffer
 	fmt.Fprintf(&versionString, "%s", Version)
 	if VersionPrerelease != "" {
-		fmt.Fprintf(&versionString, ".%s", VersionPrerelease)
+		fmt.Fprintf(&versionString, "-%s", VersionPrerelease)
 
 		if GitCommit != "" {
 			fmt.Fprintf(&versionString, " (%s)", GitCommit)