diff --git a/test/framework.cc b/test/framework.cc
index 33dfe3e..22731da 100644
--- a/test/framework.cc
+++ b/test/framework.cc
@@ -14,6 +14,9 @@
 
 #include <pEp/keymanagement.h>
 #include <pEp/mime.h>
+#include <pEp/message_api.h>
+#include <pEp/sync_codec.h>
+#include <pEp/distribution_codec.h>
 
 pEp::Test::Transport pEp::Test::transport;
 std::string pEp::Test::path;
@@ -87,7 +90,12 @@ namespace pEp {
             return shared_ptr<::message>(msg, ::free_message);
         }
 
-        Message make_message(string text)
+        Identity make_identity(::pEp_identity *ident)
+        {
+            return shared_ptr<::pEp_identity>(ident , ::free_identity);
+        }
+
+        Message mime_parse(string text)
         {
             ::message *msg;
             bool has_possible_pEp_msg;
@@ -96,7 +104,7 @@ namespace pEp {
             return make_message(msg);
         }
 
-        string make_string(Message msg)
+        string mime_compose(Message msg)
         {
             char *mimetext;
             PEP_STATUS status = ::mime_encode_message(msg.get(), false, &mimetext, false);
@@ -106,6 +114,40 @@ namespace pEp {
             return text;
         }
 
+        string make_pEp_msg(Message msg)
+        {
+            string text;
+
+            ::message *_dst;
+            stringlist_t *keylist;
+            PEP_rating rating;
+            PEP_decrypt_flags_t flags = 0;
+            PEP_STATUS status = ::decrypt_message(session(), msg.get(), &_dst, &keylist, &rating, &flags);
+            throw_status(status);
+            Message dst = make_message(_dst);
+
+            for (auto a = _dst->attachments; a && a->value; a = a->next) {
+                if (string("application/pEp.sync") == a->mime_type) {
+                    char *_text;
+                    status = PER_to_XER_Sync_msg(a->value, a->size, &_text);
+                    throw_status(status);
+                    text += _text;
+                    pEp_free(_text);
+                    return text;
+                }
+                else if (string("application/pEp.distribution") == a->mime_type) {
+                    char *_text;
+                    status = PER_to_XER_Distribution_msg(a->value, a->size, &_text);
+                    throw_status(status);
+                    text += _text;
+                    pEp_free(_text);
+                    return text;
+                }
+            }
+            
+            return text;
+        }
+
         Message Transport::recv()
         {
             mkdir(inbox_path.c_str(), 0770);
diff --git a/test/framework.hh b/test/framework.hh
index ddb8fb7..a7e2a0a 100644
--- a/test/framework.hh
+++ b/test/framework.hh
@@ -19,16 +19,24 @@ namespace pEp {
         void import_key_from_file(string filename);
 
         using Message = shared_ptr<::message>;
+        using Identity= shared_ptr<::pEp_identity>;
 
         // use this instead of constructor to auto assign ::free_message as
         // deleter
         Message make_message(::message *msg);
 
+        // use this instead of constructor to auto assign ::free_identity as
+        // deleter
+        Identity make_identity(::pEp_identity *ident);
+
         // MIME parser
-        Message make_message(string text);
+        Message mime_parse(string text);
 
         // MIME composer
-        string make_string(Message msg);
+        string mime_compose(Message msg);
+
+        // Sync and Distribution decoder
+        string make_pEp_msg(Message msg);
 
         struct Transport {
             string inbox_path = "inbox";
diff --git a/test/test_leave_device_group.cc b/test/test_leave_device_group.cc
new file mode 100644
index 0000000..9f11f97
--- /dev/null
+++ b/test/test_leave_device_group.cc
@@ -0,0 +1,84 @@
+#include <iostream>
+
+#include "framework.hh"
+#include "passphrase_cache.hh"
+#include "callback_dispatcher.hh"
+
+#include <pEp/sync_api.h>
+
+using namespace pEp;
+using namespace pEp::Adapter;
+using namespace std;
+
+PEP_STATUS test_messageToSend(::message *_msg)
+{
+    Test::Message msg = Test::make_message(_msg);
+    cerr << Test::make_pEp_msg(msg);
+    return PEP_STATUS_OK;   
+}
+
+
+PEP_STATUS test_notifyHandshake(pEp_identity *_me, pEp_identity *_partner, sync_handshake_signal signal)
+{
+    Test::Identity me = Test::make_identity(_me);
+    Test::Identity partner = Test::make_identity(_partner);
+
+    return PEP_STATUS_OK;   
+}
+
+int main(int argc, char **argv)
+{
+    Test::setup(argc, argv);
+
+    // set up two own identites for sync
+
+    passphrase_cache.add("erwin");
+    passphrase_cache.add("bob");
+
+    const char* bob_filename = ENGINE_TEST "/test_keys/bob-primary-with-password-bob-subkey-without.pgp";
+    const char* bob_fpr = "5C76378A62B04CF3F41BEC8D4940FC9FA1878736";
+
+    const char* erwin_filename = ENGINE_TEST "/test_keys/erwin_normal_encrypted.pgp";
+    const char* erwin_fpr = "CBA968BC01FCEB89F04CCF155C5E9E3F0420A570";
+
+    Test::import_key_from_file(bob_filename);
+    Test::import_key_from_file(erwin_filename);
+
+    pEp_identity* bob = ::new_identity("bob@example.org", bob_fpr, "BOB", "Bob Dog");
+    PEP_STATUS status = ::set_own_key(session(), bob, bob_fpr);
+    assert(status == PEP_STATUS_OK);
+
+    status = ::enable_identity_for_sync(session(), bob);
+    assert(status == PEP_STATUS_OK);
+
+    pEp_identity* erwin = ::new_identity("erwin@example.org", erwin_fpr, "BOB", "Bob is Erwin");
+    status = ::set_own_key(session(), erwin, erwin_fpr);
+    assert(status == PEP_STATUS_OK);
+
+    status = ::enable_identity_for_sync(session(), erwin);
+    assert(status == PEP_STATUS_OK);
+
+    // simulate a device group by setting the identities to in sync
+
+    status = set_identity_flags(session(), bob, PEP_idf_devicegroup);
+    status = set_identity_flags(session(), erwin, PEP_idf_devicegroup);
+
+    // register at callback_dispatcher and start sync
+
+    callback_dispatcher.add(test_messageToSend, test_notifyHandshake);
+    CallbackDispatcher::start_sync();
+
+
+    // stop sync
+    CallbackDispatcher::stop_sync();
+
+    // free own identities and release session and release session
+
+    ::free_identity(bob);
+    ::free_identity(erwin);
+
+    session(Adapter::release);
+
+    return 0;
+}
+