diff --git a/F-Droid/src/org/fdroid/fdroid/data/InstalledAppProvider.java b/F-Droid/src/org/fdroid/fdroid/data/InstalledAppProvider.java
index 3ce9b405e..0486c2c5f 100644
--- a/F-Droid/src/org/fdroid/fdroid/data/InstalledAppProvider.java
+++ b/F-Droid/src/org/fdroid/fdroid/data/InstalledAppProvider.java
@@ -113,6 +113,9 @@ public class InstalledAppProvider extends FDroidProvider {
     }
 
     public static String getPackageSig(PackageInfo info) {
+        if (info == null || info.signatures == null || info.signatures.length < 1) {
+            return "";
+        }
         Signature sig = info.signatures[0];
         String sigHash = "";
         try {
diff --git a/F-Droid/test/src/org/fdroid/fdroid/InstalledAppProviderTest.java b/F-Droid/test/src/org/fdroid/fdroid/InstalledAppProviderTest.java
index c81def02d..7c88b4778 100644
--- a/F-Droid/test/src/org/fdroid/fdroid/InstalledAppProviderTest.java
+++ b/F-Droid/test/src/org/fdroid/fdroid/InstalledAppProviderTest.java
@@ -158,6 +158,7 @@ public class InstalledAppProviderTest extends FDroidProviderTest<InstalledAppPro
         values.put(InstalledAppProvider.DataColumns.APPLICATION_LABEL, "Mock app: " + appId);
         values.put(InstalledAppProvider.DataColumns.VERSION_CODE, versionCode);
         values.put(InstalledAppProvider.DataColumns.VERSION_NAME, versionNumber);
+        values.put(InstalledAppProvider.DataColumns.SIGNATURE, "");
         return values;
     }