diff --git a/src/engine/api/geary-account.vala b/src/engine/api/geary-account.vala
index 7ed28141..628a14ec 100644
--- a/src/engine/api/geary-account.vala
+++ b/src/engine/api/geary-account.vala
@@ -527,7 +527,7 @@ public abstract class Geary.Account : BaseObject, Logging.Source {
      * has been flagged to run this will be executed. Designed to be run
      * while the app is in the background and idle.
      */
-    public abstract async void cleanup_storage(Cancellable? cancellable);
+    public abstract async void cleanup_storage(GLib.Cancellable? cancellable);
 
     /** Fires a {@link opened} signal. */
     protected virtual void notify_opened() {
diff --git a/src/engine/imap-db/imap-db-database.vala b/src/engine/imap-db/imap-db-database.vala
index d490d6c6..86f351b0 100644
--- a/src/engine/imap-db/imap-db-database.vala
+++ b/src/engine/imap-db/imap-db-database.vala
@@ -61,7 +61,7 @@ private class Geary.ImapDB.Database : Geary.Db.VersionedDatabase {
 
     private TimeoutManager gc_post_old_message_detach_timer;
     // Cancellable from account synchronizer for GC after old message cleanup
-    private Cancellable? post_gc_cleanup_cancellable;
+    private GLib.Cancellable? post_gc_cleanup_cancellable;
 
     public Database(GLib.File db_file,
                     GLib.File schema_dir,
@@ -99,7 +99,7 @@ private class Geary.ImapDB.Database : Geary.Db.VersionedDatabase {
      *      signify that it's an appropriate time to run a vacuum (ie. we're
      *      idle in the background) and provide access for stopping IMAP.
      */
-    public async void run_gc(Cancellable? cancellable,
+    public async void run_gc(GLib.Cancellable? cancellable,
                              bool force_reap = false,
                              Geary.ImapEngine.GenericAccount? account = null)
                                  throws Error {
@@ -210,7 +210,7 @@ private class Geary.ImapDB.Database : Geary.Db.VersionedDatabase {
         base.close(cancellable);
     }
 
-    public void schedule_gc_after_old_messages_cleanup(Cancellable? cancellable) {
+    public void schedule_gc_after_old_messages_cleanup(GLib.Cancellable? cancellable) {
         this.post_gc_cleanup_cancellable = cancellable;
         this.gc_post_old_message_detach_timer.start();
     }
diff --git a/src/engine/imap-db/imap-db-folder.vala b/src/engine/imap-db/imap-db-folder.vala
index 06ee87a7..4028be67 100644
--- a/src/engine/imap-db/imap-db-folder.vala
+++ b/src/engine/imap-db/imap-db-folder.vala
@@ -883,7 +883,7 @@ private class Geary.ImapDB.Folder : BaseObject, Geary.ReferenceSemantics {
     }
 
     public async Gee.Collection<Geary.EmailIdentifier>? detach_emails_before_timestamp(DateTime cutoff,
-        Cancellable? cancellable) throws Error {
+        GLib.Cancellable? cancellable) throws Error {
         debug("Detaching emails before %s for folder ID %", cutoff.to_string(), this.folder_id.to_string());
         Gee.Collection<Geary.EmailIdentifier>? deleted_ids = null;
 
diff --git a/src/engine/imap-engine/imap-engine-account-synchronizer.vala b/src/engine/imap-engine/imap-engine-account-synchronizer.vala
index 43916249..e4b65b42 100644
--- a/src/engine/imap-engine/imap-engine-account-synchronizer.vala
+++ b/src/engine/imap-engine/imap-engine-account-synchronizer.vala
@@ -96,7 +96,7 @@ private class Geary.ImapEngine.AccountSynchronizer :
         }
     }
 
-    private void old_messages_background_cleanup(Cancellable? cancellable) {
+    private void old_messages_background_cleanup(GLib.Cancellable? cancellable) {
        if (this.account.is_open()) {
             this.old_message_cleaner = new OldMessageCleaner(this.account, this.max_epoch);
             this.old_message_cleaner.run();
@@ -107,7 +107,7 @@ private class Geary.ImapEngine.AccountSynchronizer :
         }
     }
 
-    private void old_messages_removed_during_sync(Cancellable cancellable) {
+    private void old_messages_removed_during_sync(GLib.Cancellable cancellable) {
         if (this.old_message_cleaner == null) {
             // This is not a daily cleanup. We've detached some messages, let's GC if
             // recommended.
@@ -246,7 +246,7 @@ private class Geary.ImapEngine.RefreshFolderSync : FolderOperation {
  */
 private class Geary.ImapEngine.CheckFolderSync : RefreshFolderSync {
 
-    public signal void old_message_detached(Cancellable cancellable);
+    public signal void old_message_detached(GLib.Cancellable cancellable);
 
     private DateTime sync_max_epoch;
 
diff --git a/src/engine/imap-engine/imap-engine-generic-account.vala b/src/engine/imap-engine/imap-engine-generic-account.vala
index da5bec38..e221bfa3 100644
--- a/src/engine/imap-engine/imap-engine-generic-account.vala
+++ b/src/engine/imap-engine/imap-engine-generic-account.vala
@@ -43,7 +43,7 @@ private abstract class Geary.ImapEngine.GenericAccount : Geary.Account {
     /** Local database for the account. */
     public ImapDB.Account local { get; private set; }
 
-    public signal void old_messages_background_cleanup_request(Cancellable? cancellable);
+    public signal void old_messages_background_cleanup_request(GLib.Cancellable? cancellable);
 
     private bool open = false;
     private Cancellable? open_cancellable = null;
@@ -531,7 +531,7 @@ private abstract class Geary.ImapEngine.GenericAccount : Geary.Account {
     }
 
     /** {@inheritDoc} */
-    public override async void cleanup_storage(Cancellable? cancellable) {
+    public override async void cleanup_storage(GLib.Cancellable? cancellable) {
         debug("Backgrounded storage cleanup check for %s account", this.information.display_name);
 
         DateTime now = new DateTime.now_local();
@@ -550,7 +550,7 @@ private abstract class Geary.ImapEngine.GenericAccount : Geary.Account {
 
     // Continue backgrounded app cleanup work after the first phase,
     // old message detachment, has completed
-    public void app_backgrounded_cleanup_continued(bool messages_detached, Cancellable? cancellable) {
+    public void app_backgrounded_cleanup_continued(bool messages_detached, GLib.Cancellable? cancellable) {
         // TODO bail on remaining work if we've returned from the background
         // if (!application.controller.all_windows_backgrounded)
         //    return;
diff --git a/test/engine/api/geary-account-mock.vala b/test/engine/api/geary-account-mock.vala
index f7b63f4c..9ee59c43 100644
--- a/test/engine/api/geary-account-mock.vala
+++ b/test/engine/api/geary-account-mock.vala
@@ -274,7 +274,7 @@ public class Geary.MockAccount : Account, MockObject {
         );
     }
 
-    public override async void cleanup_storage(Cancellable? cancellable) {
+    public override async void cleanup_storage(GLib.Cancellable? cancellable) {
 
     }
 }