diff --git a/src/Core/FlatpakBackend.vala b/src/Core/FlatpakBackend.vala
index c1efd07be..930baf193 100644
--- a/src/Core/FlatpakBackend.vala
+++ b/src/Core/FlatpakBackend.vala
@@ -17,6 +17,9 @@
  * Authored by: David Hewitt <davidmhewitt@gmail.com>
  */
 
+[CCode (cheader_filename = "malloc.h")]
+extern int malloc_trim (size_t pad);
+
 public class AppCenterCore.FlatpakPackage : Package {
     public weak Flatpak.Installation installation { public get; construct; }
 
@@ -129,6 +132,10 @@ public class AppCenterCore.FlatpakBackend : Object, Backend {
     private static GLib.FileMonitor user_installation_changed_monitor;
     private static GLib.FileMonitor system_installation_changed_monitor;
 
+    private uint installation_changed_timeout_id = 0;
+    private bool update_check_running = false;
+    private bool update_check_pending = false;
+
     private uint total_operations;
     private int current_operation;
 
@@ -295,21 +302,7 @@ public class AppCenterCore.FlatpakBackend : Object, Backend {
                 warning ("Couldn't user create Installation File Monitor : %s", e.message);
             }
 
-            user_installation_changed_monitor.changed.connect (() => {
-                if (!working) {
-                    debug ("Flatpak user installation changed.");
-
-                    // Clear the installed state of all packages as something may have changed we weren't
-                    // aware of
-                    foreach (var package in package_list.values) {
-                        if (package.state != Package.State.NOT_INSTALLED || package.installed) {
-                            package.clear_installed ();
-                        }
-                    }
-
-                    trigger_update_check.begin ();
-                }
-            });
+            user_installation_changed_monitor.changed.connect (() => queue_installation_changed_check ());
         } else {
             warning ("Couldn't create user Installation File Monitor due to no installation");
         }
@@ -321,24 +314,10 @@ public class AppCenterCore.FlatpakBackend : Object, Backend {
                 warning ("Couldn't create system Installation File Monitor : %s", e.message);
             }
 
-            system_installation_changed_monitor.changed.connect (() => {
-                // Only trigger a cache refresh if we're not doing anything (i.e. its an external change)
-                if (!working) {
-                    debug ("Flatpak system installation changed.");
-
-                    // Clear the installed state of all packages as something may have changed we weren't
-                    // aware of
-                    foreach (var package in package_list.values) {
-                        if (package.state != Package.State.NOT_INSTALLED || package.installed) {
-                            package.clear_installed ();
-                        }
-                    }
-
-                    // Reloads the appstream data for enabled remotes and checks what applications are
-                    // installed/require updates
-                    trigger_update_check.begin ();
-                }
-            });
+            // Only trigger a cache refresh if we're not doing anything (i.e. its an external change).
+            // Reloads the appstream data for enabled remotes and checks what applications are
+            // installed/require updates.
+            system_installation_changed_monitor.changed.connect (() => queue_installation_changed_check ());
         } else {
             warning ("Couldn't create system Installation File Monitor due to no installation");
         }
@@ -423,15 +402,50 @@ public class AppCenterCore.FlatpakBackend : Object, Backend {
         });
     }
 
+    private void queue_installation_changed_check () {
+        if (installation_changed_timeout_id != 0) {
+            Source.remove (installation_changed_timeout_id);
+        }
+
+        installation_changed_timeout_id = Timeout.add_seconds_once (2, () => {
+            installation_changed_timeout_id = 0;
+
+            debug ("Flatpak installation changed (debounced); triggering update check.");
+
+            // Clear the installed state of all packages as something may have changed
+            // we weren't aware of
+            foreach (var package in package_list.values) {
+                if (package.state != Package.State.NOT_INSTALLED || package.installed) {
+                    package.clear_installed ();
+                }
+            }
+
+            trigger_update_check.begin ();
+        });
+    }
+
     private async void trigger_update_check () {
-        try {
-            yield refresh_cache (null);
-        } catch (Error e) {
-            warning ("Unable to refresh cache after external change: %s", e.message);
+        if (update_check_running) {
+            update_check_pending = true;
+            return;
         }
 
-        reload_installed_packages ();
-        yield get_updates (null);
+        update_check_running = true;
+
+        do {
+            update_check_pending = false;
+
+            try {
+                yield refresh_cache (null);
+            } catch (Error e) {
+                warning ("Unable to refresh cache after external change: %s", e.message);
+            }
+
+            reload_installed_packages ();
+            yield get_updates (null);
+        } while (update_check_pending);
+
+        update_check_running = false;
     }
 
     static construct {
@@ -2067,6 +2081,8 @@ public class AppCenterCore.FlatpakBackend : Object, Backend {
         }
 
         fill_runtime_updates ();
+
+        malloc_trim (0);
     }
 
     private void repair_internal (Job job) {