diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyOperation.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyOperation.java
index 5e7eb0a4a..40a0b72ce 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyOperation.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyOperation.java
@@ -432,7 +432,7 @@ public class PgpKeyOperation {
         // TODO: this only takes care of user id certificates, what about others?
         PGPPublicKey pubkey = publicKeyRing.getPublicKey();
         for(String uid : new IterableIterator<String>(pubkey.getUserIDs())) {
-            for(PGPSignature sig : new IterableIterator<PGPSignature>(oldPublicKey.getSignaturesForID(uid))) {
+            for(PGPSignature sig : new IterableIterator<PGPSignature>(oldPublicKey.getSignaturesForID(uid), true)) {
                 // but skip self certificates
                 if(sig.getKeyID() == pubkey.getKeyID())
                     continue;
diff --git a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/util/IterableIterator.java b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/util/IterableIterator.java
index caaa07524..40105df4f 100644
--- a/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/util/IterableIterator.java
+++ b/OpenPGP-Keychain/src/main/java/org/sufficientlysecure/keychain/util/IterableIterator.java
@@ -16,13 +16,21 @@
 
 package org.sufficientlysecure.keychain.util;
 
+import java.util.ArrayList;
 import java.util.Iterator;
 
 public class IterableIterator<T> implements Iterable<T> {
     private Iterator<T> mIter;
 
-    public IterableIterator(Iterator<T> iter) {
+    public IterableIterator(Iterator<T> iter, boolean failsafe) {
         mIter = iter;
+        if(failsafe && mIter == null) {
+            // is there a better way?
+            mIter = new ArrayList<T>().iterator();
+        }
+    }
+    public IterableIterator(Iterator<T> iter) {
+        this(iter, false);
     }
 
     public Iterator<T> iterator() {