diff --git a/src/pimcommonakonadi/acl/collectionaclpage.cpp b/src/pimcommonakonadi/acl/collectionaclpage.cpp
--- a/src/pimcommonakonadi/acl/collectionaclpage.cpp
+++ b/src/pimcommonakonadi/acl/collectionaclpage.cpp
@@ -88,6 +88,11 @@
 
     // The collection dialog expects the changed collection to run
     // its own ItemModifyJob, so make him happy...
-    PimCommon::ImapAclAttribute *attribute = d->mCollectionAclWidget->aclManager()->collection().attribute<PimCommon::ImapAclAttribute>();
+    Akonadi::Collection c = d->mCollectionAclWidget->aclManager()->collection();
+    if (c.isValid()) {
+        PimCommon::ImapAclAttribute *attribute = c.attribute<PimCommon::ImapAclAttribute>();
+        if (attribute) {
             collection.addAttribute(attribute->clone());
         }
+    }
+}