diff --git a/app/dashboard/templates/dashboard/custom_alias.html b/app/dashboard/templates/dashboard/custom_alias.html
index 5380759c..4980a74b 100644
--- a/app/dashboard/templates/dashboard/custom_alias.html
+++ b/app/dashboard/templates/dashboard/custom_alias.html
@@ -19,13 +19,13 @@
       <div class="form-group">
         <label class="form-label">Custom Alias</label>
         <small class="text-muted">
-          Email must use alphanumeric characters and must be at least 3 characters
+          You can use letter, number or dash. Alias must have at least 3 characters
         </small>
         <div class="row mt-4">
           <div class="col">
             {{ form.email(class="form-control",
-                pattern="[0-9|A-Z|a-z]{3,}",
-                title="Email must use alphanumeric characters and must be at least 3 characters.") }}
+                pattern="[0-9|A-Z|a-z|-]{3,}",
+                title="Only letter, number or dash can be used and alias must have at least 3 characters.") }}
             {{ render_field_errors(form.email) }}
           </div>
           <div class="col align-self-center">
diff --git a/app/oauth/templates/oauth/authorize.html b/app/oauth/templates/oauth/authorize.html
index 2a33ad0b..1206b11e 100644
--- a/app/oauth/templates/oauth/authorize.html
+++ b/app/oauth/templates/oauth/authorize.html
@@ -94,7 +94,8 @@
               <div class="mt-2">OR</div>
               <div style="display: flex; align-items: center" class="mt-2">
                 <input class="form-control"
-                       pattern="[0-9|A-Z|a-z]{3,}"
+                       pattern="[0-9|A-Z|a-z|-]{3,}"
+                       title="Only letter, number or dash can be used and alias must have at least 3 characters."
                        style="flex-grow: 2" name="custom-email-prefix">
                 <input type="hidden" name="email-suffix" value="{{ email_suffix }}">
                 <div class="ml-2">
@@ -102,7 +103,7 @@
                 </div>
               </div>
               <small class="text-muted">
-                Custom alias use alphanumeric characters and must be at least 3 characters
+                Alias can use letter, number, dash and must be at least 3 characters
               </small>
             {% endif %}
           </div>