diff --git a/src/main/java/JettyLauncher.java b/src/main/java/JettyLauncher.java
index 70044c9..274654a 100644
--- a/src/main/java/JettyLauncher.java
+++ b/src/main/java/JettyLauncher.java
@@ -51,6 +51,9 @@
                         case "--plugin_dir":
                             System.setProperty("gitbucket.pluginDir", dim[1]);
                             break;
+                        case "--validate_password":
+                            System.setProperty("gitbucket.validate.password", dim[1]);
+                            break;
                     }
                 }
             }
diff --git a/src/main/scala/gitbucket/core/util/Validations.scala b/src/main/scala/gitbucket/core/util/Validations.scala
index f34a1ee..6cd693c 100644
--- a/src/main/scala/gitbucket/core/util/Validations.scala
+++ b/src/main/scala/gitbucket/core/util/Validations.scala
@@ -24,7 +24,7 @@
    */
   def password: Constraint = new Constraint(){
     override def validate(name: String, value: String, messages: Messages): Option[String] =
-      if(!value.matches("[a-zA-Z0-9\\-_.]+")){
+      if(System.getProperty("gitbucket.validate.password") != "false" && !value.matches("[a-zA-Z0-9\\-_.]+")){
         Some(s"${name} contains invalid character.")
       } else {
         None