diff --git a/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProvider.java b/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProvider.java
index 9b3d01877..166d838f0 100644
--- a/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProvider.java
+++ b/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProvider.java
@@ -27,12 +27,12 @@ public class InstalledAppProvider extends FDroidProvider {
     public static class Helper {
 
         /**
-         * @return The keys are the app ids (package names), and their corresponding values are
-         * the version code which is installed.
+         * @return The keys are the package names, and their corresponding values are
+         * the {@link PackageInfo#lastUpdateTime last update time} in milliseconds.
          */
-        public static Map<String, Integer> all(Context context) {
+        public static Map<String, Long> all(Context context) {
 
-            Map<String, Integer> cachedInfo = new HashMap<>();
+            Map<String, Long> cachedInfo = new HashMap<>();
 
             final Uri uri = InstalledAppProvider.getContentUri();
             final String[] projection = InstalledAppProvider.DataColumns.ALL;
@@ -43,7 +43,7 @@ public class InstalledAppProvider extends FDroidProvider {
                     while (!cursor.isAfterLast()) {
                         cachedInfo.put(
                                 cursor.getString(cursor.getColumnIndex(InstalledAppProvider.DataColumns.PACKAGE_NAME)),
-                                cursor.getInt(cursor.getColumnIndex(InstalledAppProvider.DataColumns.VERSION_CODE))
+                                cursor.getLong(cursor.getColumnIndex(DataColumns.LAST_UPDATE_TIME))
                         );
                         cursor.moveToNext();
                     }
@@ -223,6 +223,11 @@ public class InstalledAppProvider extends FDroidProvider {
         return getAppUri(values.getAsString(DataColumns.PACKAGE_NAME));
     }
 
+    /**
+     * Update is not supported for {@code InstalledAppProvider}. Instead, use
+     * {@link #insert(Uri, ContentValues)}, and it will overwrite the relevant
+     * row, if one exists.  This just throws {@link UnsupportedOperationException}
+     */
     @Override
     public int update(Uri uri, ContentValues values, String where, String[] whereArgs) {
         throw new UnsupportedOperationException("\"Update' not supported for installed appp provider. Instead, you should insert, and it will overwrite the relevant rows if one exists.");
diff --git a/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java b/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java
index acd5a8d45..3dc103bac 100644
--- a/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java
+++ b/app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java
@@ -23,7 +23,7 @@ import java.util.concurrent.TimeUnit;
  * versus what Android says is installed, or processing {@link Intent}s that come
  * from {@link android.content.BroadcastReceiver}s for {@link Intent#ACTION_PACKAGE_ADDED}
  * and {@link Intent#ACTION_PACKAGE_REMOVED}
- * <p>
+ * <p/>
  * Since {@link android.content.ContentProvider#insert(Uri, ContentValues)} does not check
  * for duplicate records, it is entirely the job of this service to ensure that it is not
  * inserting duplicate versions of the same installed APK. On that note,
@@ -94,7 +94,7 @@ public class InstalledAppProviderService extends IntentService {
      * is in sync with what the {@link PackageManager} tells us is installed. Once
      * completed, the relevant {@link android.content.ContentProvider}s will be
      * notified of any changes to installed statuses.
-     * <p>
+     * <p/>
      * The installed app cache could get out of sync, e.g. if F-Droid crashed/ or
      * ran out of battery half way through responding to {@link Intent#ACTION_PACKAGE_ADDED}.
      * This method returns immediately, and will continue to work in an
@@ -103,15 +103,18 @@ public class InstalledAppProviderService extends IntentService {
      * {@link Process#THREAD_PRIORITY_LOWEST}.
      */
     public static void compareToPackageManager(Context context) {
-        Map<String, Integer> cachedInfo = InstalledAppProvider.Helper.all(context);
+        Map<String, Long> cachedInfo = InstalledAppProvider.Helper.all(context);
 
         List<PackageInfo> packageInfoList = context.getPackageManager()
                 .getInstalledPackages(PackageManager.GET_SIGNATURES);
-        // TODO check packageInfo.lastUpdateTime for freshness
         for (PackageInfo packageInfo : packageInfoList) {
-            insert(context, packageInfo);
             if (cachedInfo.containsKey(packageInfo.packageName)) {
+                if (packageInfo.lastUpdateTime > cachedInfo.get(packageInfo.packageName)) {
+                    insert(context, packageInfo);
+                }
                 cachedInfo.remove(packageInfo.packageName);
+            } else {
+                insert(context, packageInfo);
             }
         }