diff --git a/src/db/models/user.rs b/src/db/models/user.rs
index 888d3f5..0225432 100644
--- a/src/db/models/user.rs
+++ b/src/db/models/user.rs
@@ -137,6 +137,10 @@ impl User {
     }
 
     pub fn save(&mut self, conn: &DbConn) -> EmptyResult {
+        if self.email.trim().is_empty() {
+            err!("User email can't be empty")
+        }
+
         self.updated_at = Utc::now().naive_utc();
 
         diesel::replace_into(users::table) // Insert or update
@@ -213,6 +217,10 @@ impl Invitation {
     }
 
     pub fn save(&mut self, conn: &DbConn) -> EmptyResult {
+        if self.email.trim().is_empty() {
+            err!("Invitation email can't be empty")
+        }
+
         diesel::replace_into(invitations::table)
             .values(&*self)
             .execute(&**conn)
diff --git a/src/static/templates/admin/page.hbs b/src/static/templates/admin/page.hbs
index 8847f5b..538eda8 100644
--- a/src/static/templates/admin/page.hbs
+++ b/src/static/templates/admin/page.hbs
@@ -65,7 +65,7 @@
     }
     function deleteUser(id, mail) {
         var input_mail = prompt("To delete user '" + mail + "', please type the name below")
-        if (input_mail) {
+        if (input_mail != null) {
             if (input_mail == mail) {
                 _post("/admin/users/" + id + "/delete",
                     "User deleted correctly",