diff --git a/src/RemoteSerializer.cc b/src/RemoteSerializer.cc
index 564ad2be68..54986610bc 100644
--- a/src/RemoteSerializer.cc
+++ b/src/RemoteSerializer.cc
@@ -1032,6 +1032,14 @@ bool RemoteSerializer::SendAllSynchronized(Peer* peer, SerialInfo* info)
 
 	for ( ; index < sync_ids.length(); ++index )
 		{
+		if ( ! sync_ids[index]->ID_Val() )
+			{
+#ifdef DEBUG
+			DBG_LOG(DBG_COMM, "Skip sync of ID with null value: %s\n",
+			        sync_ids[index]->Name());
+#endif
+			continue;
+			}
 		cont->SaveContext();
 
 		StateAccess sa(OP_ASSIGN, sync_ids[index],
diff --git a/testing/btest/Baseline/istate.sync/receiver.vars.log b/testing/btest/Baseline/istate.sync/receiver.vars.log
index b28cfbd5c9..192876bd3e 100644
--- a/testing/btest/Baseline/istate.sync/receiver.vars.log
+++ b/testing/btest/Baseline/istate.sync/receiver.vars.log
@@ -31,3 +31,4 @@ file "test2" of string
 6667/tcp
 [2, 20, 3, 4]
 [a=zxzxzx, b=[a=pop, b=43, c=9.999], c=[a=IOIOI, b=201, c=612.2], d=6.6666, e=<uninitialized>]
+122112
diff --git a/testing/btest/Baseline/istate.sync/sender.vars.log b/testing/btest/Baseline/istate.sync/sender.vars.log
index b28cfbd5c9..192876bd3e 100644
--- a/testing/btest/Baseline/istate.sync/sender.vars.log
+++ b/testing/btest/Baseline/istate.sync/sender.vars.log
@@ -31,3 +31,4 @@ file "test2" of string
 6667/tcp
 [2, 20, 3, 4]
 [a=zxzxzx, b=[a=pop, b=43, c=9.999], c=[a=IOIOI, b=201, c=612.2], d=6.6666, e=<uninitialized>]
+122112
diff --git a/testing/btest/istate/sync.bro b/testing/btest/istate/sync.bro
index e1364a9553..a297e8a50f 100644
--- a/testing/btest/istate/sync.bro
+++ b/testing/btest/istate/sync.bro
@@ -1,7 +1,7 @@
 # @TEST-SERIALIZE: comm
 #
-# @TEST-EXEC: btest-bg-run sender   bro %INPUT ../sender.bro
-# @TEST-EXEC: btest-bg-run receiver bro %INPUT ../receiver.bro
+# @TEST-EXEC: btest-bg-run sender   bro -b %INPUT ../sender.bro
+# @TEST-EXEC: btest-bg-run receiver bro -b %INPUT ../receiver.bro
 # @TEST-EXEC: btest-bg-wait 20
 #
 # @TEST-EXEC: btest-diff sender/vars.log
@@ -27,6 +27,7 @@ global foo13  =  { [1,"ABC"] = 101, [2,"DEF"] = 102, [3,"GHI"] = 103 } &persiste
 global foo14  =  { [12345] = foo11, [12346] = foo11 } &persistent &synchronized;
 global foo15 = 42/udp &persistent &synchronized;
 global foo16: vector of count = [1,2,3] &persistent &synchronized;
+global foo18: count &persistent &synchronized;  # not initialized
  
 type type1: record {
     a: string;
@@ -70,6 +71,7 @@ event bro_done()
 	print out, foo15;
 	print out, foo16;
 	print out, foo17;
+	print out, foo18;
 	}
 
 
@@ -128,7 +130,8 @@ function modify()
 	delete foo17$e;
 	
 	foo2 = 1234567;
-}
+	foo18 = 122112;
+	}
 
 @load frameworks/communication/listen
 
@@ -148,6 +151,8 @@ redef Communication::nodes += {
 
 @TEST-START-FILE receiver.bro
 
+@load base/frameworks/communication
+
 event bro_init()
     {
     capture_events("events.bst");