diff --git a/main.go b/main.go
index 0063e5664..4f0be780f 100644
--- a/main.go
+++ b/main.go
@@ -17,12 +17,18 @@ package main
 import (
 	"github.com/runatlantis/atlantis/cmd"
 	"github.com/spf13/viper"
+	"strings"
 )
 
 const atlantisVersion = "0.3.3"
 
 func main() {
 	v := viper.New()
+	// Get environment variables with ATLANTIS prefix
+	v.SetEnvPrefix("ATLANTIS")
+	replacer := strings.NewReplacer("-","_")
+	v.SetEnvKeyReplacer(replacer)
+	v.AutomaticEnv()
 
 	// We're creating commands manually here rather than using init() functions
 	// (as recommended by cobra) because it makes testing easier.