diff --git a/app/auto_scale.go b/app/auto_scale.go
index <HASH>..<HASH> 100644
--- a/app/auto_scale.go
+++ b/app/auto_scale.go
@@ -23,7 +23,7 @@ type Action struct {
 }
 
 func NewAction(expression string, units uint, wait time.Duration) (*Action, error) {
-	if validateExpression(expression) {
+	if expressionIsValid(expression) {
 		return &Action{Wait: wait, Expression: expression, Units: units}, nil
 	}
 	return nil, errors.New("Expression is not valid.")
@@ -31,7 +31,7 @@ func NewAction(expression string, units uint, wait time.Duration) (*Action, erro
 
 var expressionRegex = regexp.MustCompile("{(.*)} ([><=]) ([0-9]+)")
 
-func validateExpression(expression string) bool {
+func expressionIsValid(expression string) bool {
 	return expressionRegex.MatchString(expression)
 }
 
diff --git a/app/auto_scale_test.go b/app/auto_scale_test.go
index <HASH>..<HASH> 100644
--- a/app/auto_scale_test.go
+++ b/app/auto_scale_test.go
@@ -181,7 +181,7 @@ func (s *S) TestValidateExpression(c *gocheck.C) {
 		"100":        false,
 	}
 	for expression, expected := range cases {
-		c.Assert(validateExpression(expression), gocheck.Equals, expected)
+		c.Assert(expressionIsValid(expression), gocheck.Equals, expected)
 	}
 }
aut scale: renamed validateExpression to expressionIsValid.

related to #<I>.