diff --git a/app/src/main/java/org/fdroid/fdroid/installer/ApkCache.java b/app/src/main/java/org/fdroid/fdroid/installer/ApkCache.java
index b0dc8b3b8..ce627283b 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/ApkCache.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/ApkCache.java
@@ -151,8 +151,12 @@ public class ApkCache {
         if (dir == null) {
             return;
         }
+        File[] files = dir.listFiles();
+        if (files == null) {
+            return;
+        }
         long olderThan = System.currentTimeMillis() - (secondsAgo * 1000L);
-        for (File f : dir.listFiles()) {
+        for (File f : files) {
             if (f.isDirectory()) {
                 clearOldFiles(f, olderThan);
                 f.delete();