diff --git a/lib/message.cc b/lib/message.cc
index bd3cb5af..54609fcd 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -169,7 +169,7 @@ _notmuch_message_create_for_document (const void *talloc_owner,
 
     message->doc = doc;
     message->termpos = 0;
-    message->modified = FALSE;
+    message->modified = false;
 
     return message;
 }