1 files changed, 4 insertions, 1 deletions
diff --git a/src/main/java/de/pixart/messenger/persistance/FileBackend.java b/src/main/java/de/pixart/messenger/persistance/FileBackend.java
index da7ed84dc..d670c98d9 100644
--- a/src/main/java/de/pixart/messenger/persistance/FileBackend.java
+++ b/src/main/java/de/pixart/messenger/persistance/FileBackend.java
@@ -60,6 +60,9 @@ import de.pixart.messenger.utils.MimeUtils;
 import de.pixart.messenger.xmpp.pep.Avatar;
 
 public class FileBackend {
+
+    private static final Object THUMBNAIL_LOCK = new Object();
+
     private static final SimpleDateFormat fileDateFormat = new SimpleDateFormat("yyyyMMdd_HHmmssSSS", Locale.US);
 
     private static final String FILE_PROVIDER = ".files";
@@ -430,7 +433,7 @@ public class FileBackend {
         final LruCache<String, Bitmap> cache = mXmppConnectionService.getBitmapCache();
         Bitmap thumbnail = cache.get(uuid);
         if ((thumbnail == null) && (!cacheOnly)) {
-            synchronized (cache) {
+            synchronized (THUMBNAIL_LOCK) {
                 thumbnail = cache.get(uuid);
                 if (thumbnail != null) {
                     return thumbnail;