diff --git a/manifests/defines.pp b/manifests/defines.pp
index ff6adf1..b4d8a22 100644
--- a/manifests/defines.pp
+++ b/manifests/defines.pp
@@ -56,6 +56,10 @@ define user::managed(
         default => $shell,
     }
 
+    if strlength($name) > 32 {
+      fail("Usernames can't be longer than 32 characters. ${name} is too long!")
+    }
+
     user { $name:
         ensure => $ensure,
         allowdupe => false,