diff --git a/index.html b/index.html
index 5dd5b30..a320d23 100644
--- a/index.html
+++ b/index.html
@@ -992,7 +992,7 @@ <h3>Drop us a line</h3>
                                value="" required>
                     </div>
                     <div class="form-group">
-                        <input type="phone" class="form-control" id="phone" name="mobile"
+                        <input type="phone" class="form-control" pattern="^\d{10}$" title ="Phone number must be a 10 digit integer." id="phone" name="mobile"
                                placeholder="Your phone..." value="" required>
                     </div>
                     <div class="form-group">