diff --git a/src/engine/imap/command/imap-create-command.vala b/src/engine/imap/command/imap-create-command.vala
index 5da3d1e8..f09d8bc7 100644
--- a/src/engine/imap/command/imap-create-command.vala
+++ b/src/engine/imap/command/imap-create-command.vala
@@ -15,7 +15,10 @@ public class Geary.Imap.CreateCommand : Command {
     public const string USE = "use";
 
     public MailboxSpecifier mailbox { get; private set; }
-    public Geary.SpecialFolderType? use { get; private set; default = null; }
+
+    public Geary.SpecialFolderType use {
+        get; private set; default = Geary.SpecialFolderType.NONE;
+    }
 
 
     private static MailboxAttribute? get_special_folder_type(Geary.SpecialFolderType type) {
@@ -52,8 +55,10 @@ public class Geary.Imap.CreateCommand : Command {
         add(mailbox.to_parameter());
     }
 
-    public CreateCommand.special_use(MailboxSpecifier mailbox, Geary.SpecialFolderType use) {
+    public CreateCommand.special_use(MailboxSpecifier mailbox,
+                                     Geary.SpecialFolderType use) {
         this(mailbox);
+        this.use = use;
 
         MailboxAttribute? attr = get_special_folder_type(use);
         if (attr != null) {
diff --git a/src/engine/rfc822/rfc822-message.vala b/src/engine/rfc822/rfc822-message.vala
index a2e2868a..267203ab 100644
--- a/src/engine/rfc822/rfc822-message.vala
+++ b/src/engine/rfc822/rfc822-message.vala
@@ -211,7 +211,7 @@ public class Geary.RFC822.Message : BaseObject {
                     string cid = "";
                     do {
                         cid = CID_TEMPLATE.printf(cid_index++);
-                    } while (cid in email.cid_files);
+                    } while (email.cid_files.has_key(cid));
 
                     if (email.replace_inline_img_src(name,
                                                      CID_URL_PREFIX + cid)) {