diff --git a/Classes/ContactsListTableView.m b/Classes/ContactsListTableView.m
index 00e73040e..1e2f995b5 100644
--- a/Classes/ContactsListTableView.m
+++ b/Classes/ContactsListTableView.m
@@ -65,8 +65,9 @@ static void sync_address_book(ABAddressBookRef addressBook, CFDictionaryRef info
 }
 
 - (void)dealloc {
-	ABAddressBookUnregisterExternalChangeCallback(addressBook, sync_address_book, (__bridge void *)(self));
-	CFRelease(addressBook);
+	if (addressBook) {
+		ABAddressBookUnregisterExternalChangeCallback(addressBook, sync_address_book, (__bridge void *)(self));
+	}
 }
 
 #pragma mark -