diff --git a/docs/release-notes.md b/docs/release-notes.md
index c8448fb77d..26561b2e59 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -40,6 +40,7 @@ Example usage in html file: `<link rel="shortcut icon" href="#{assets['img/logo/
 * [1165930](https://bugzilla.redhat.com/show_bug.cgi?id=1165930) - 'Copy from previous version' shows if an obsolete version exists
 * [1098362](https://bugzilla.redhat.com/show_bug.cgi?id=1098362) - download link in editor doesn't encode properly and result in 404
 * [1225689](https://bugzilla.redhat.com/show_bug.cgi?id=1225689) - [Project Version View] Failed to load entries when the doc id contains characters that should be URL encoded
+* [981498](https://bugzilla.redhat.com/show_bug.cgi?id=981498) - No underscore sanity checking on creating usernames
 
 -----------------------
 
diff --git a/functional-test/src/test/java/org/zanata/feature/account/RegisterTest.java b/functional-test/src/test/java/org/zanata/feature/account/RegisterTest.java
index 682ef1249a..e77b6834e8 100644
--- a/functional-test/src/test/java/org/zanata/feature/account/RegisterTest.java
+++ b/functional-test/src/test/java/org/zanata/feature/account/RegisterTest.java
@@ -212,7 +212,7 @@ public void togglePasswordVisible() {
     @Feature(summary = "The user must enter at least one alphanumeric " +
             "character in their username",
             bugzilla = 981498)
-    @Test(expected = AssertionError.class)
+    @Test
     public void bug981498_underscoreRules() {
         fields.put("email", "bug981498test@example.com");
         fields.put("username", "______");
diff --git a/zanata-war/src/main/java/org/zanata/action/RegisterAction.java b/zanata-war/src/main/java/org/zanata/action/RegisterAction.java
index 812da7d1fb..fd6d647355 100644
--- a/zanata-war/src/main/java/org/zanata/action/RegisterAction.java
+++ b/zanata-war/src/main/java/org/zanata/action/RegisterAction.java
@@ -91,7 +91,7 @@ public void setUsername(String username) {
 
     @NotEmpty
     @Size(min = 3, max = 20)
-    @Pattern(regexp = "^[a-z\\d_]{3,20}$",
+    @Pattern(regexp = "^([a-z\\d][a-z\\d_]*){3,20}$",
             message = "{validation.username.constraints}")
     public String getUsername() {
         return username;