diff --git a/WEB-INF/vue/signin.jsp b/WEB-INF/vue/signin.jsp
index 77998178e20416a82137efb03489a70412941b32..f26c5c8eb8acbba05d1b1ecaef54885febb07df5 100644
--- a/WEB-INF/vue/signin.jsp
+++ b/WEB-INF/vue/signin.jsp
@@ -38,11 +38,11 @@
                         </div>
                         <div class="mt-2 mb-3">
                             <p class="mb-1">Prénom</p>
-                            <input class="form-control" name="firstname" type="text" placeholder="Philippe" maxlength="50" required>
+                            <input class="form-control" name="firstname" pattern="[a-zA-Z-]{3,50}" type="text" placeholder="Philippe" maxlength="50" required>
                         </div>
                         <div class="mt-2 mb-3">
                             <p class="mb-1">Nom de famille</p>
-                            <input class="form-control" name="lastname" type="text" placeholder="Mathieu" maxlength="50" required>
+                            <input class="form-control" name="lastname" pattern="[a-zA-Z-]{3,50}" type="text" placeholder="Mathieu" maxlength="50" required>
                         </div>
                     </div>
                     <div class="mt-5 d-flex flex-column justify-content-center">