diff --git a/core/src/main/java/de/danoeh/antennapod/core/sync/GuidValidator.java b/core/src/main/java/de/danoeh/antennapod/core/sync/GuidValidator.java
index 6d80a6457..74e5d5cdf 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/sync/GuidValidator.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/sync/GuidValidator.java
@@ -4,7 +4,8 @@ public class GuidValidator {
 
     public static boolean isValidGuid(String guid) {
         return guid != null
-                && !guid.trim().isEmpty();
+                && !guid.trim().isEmpty()
+                && !guid.equals("null");
     }
 }