diff --git a/src/main/scala/util/Validations.scala b/src/main/scala/util/Validations.scala
index 0a1e9ef..e422e77 100644
--- a/src/main/scala/util/Validations.scala
+++ b/src/main/scala/util/Validations.scala
@@ -9,7 +9,7 @@
    */
   def identifier: Constraint = new Constraint(){
     override def validate(name: String, value: String): Option[String] =
-      if(!value.matches("^[a-zA-Z0-9\\\\-_.]+$")){
+      if(!value.matches("^[a-zA-Z0-9\\-_\\.]+$")){
         Some(s"${name} contains invalid character.")
       } else if(value.startsWith("_") || value.startsWith("-")){
         Some(s"${name} starts with invalid character.")
diff --git a/src/test/scala/util/ValidationsSpec.scala b/src/test/scala/util/ValidationsSpec.scala
index f383c46..c1de76b 100644
--- a/src/test/scala/util/ValidationsSpec.scala
+++ b/src/test/scala/util/ValidationsSpec.scala
@@ -2,11 +2,12 @@
 
 import org.specs2.mutable._
 
-class ValidationsSpec extends Specification with Validations {
+class
+ValidationsSpec extends Specification with Validations {
 
   "identifier" should {
     "validate id string " in {
-      identifier.validate("id", "aa_ZZ-01") mustEqual None
+      identifier.validate("id", "aa_ZZ-00.01") mustEqual None
       identifier.validate("id", "_aaaa") mustEqual Some("id starts with invalid character.")
       identifier.validate("id", "-aaaa") mustEqual Some("id starts with invalid character.")
       identifier.validate("id", "aa_ZZ#01") mustEqual Some("id contains invalid character.")