diff --git a/client/client.go b/client/client.go
index 19d4235..4e28a0e 100644
--- a/client/client.go
+++ b/client/client.go
@@ -95,11 +95,10 @@ func (c *Client) send(chat Chat, t protobuf.Message_MessageType, body []byte) (s
 	c.Lock()
 	defer c.Unlock()
 
-	lastMessage := c.lastMessages[chat]
 	msg := &protobuf.Message{
 		MessageType:     protobuf.Message_MessageType(t),
 		Body:            body,
-		PreviousMessage: lastMessage[:],
+		PreviousMessage: c.lastMessage(chat),
 	}
 
 	err := crypto.Sign(c.identity, msg)
@@ -173,3 +172,12 @@ func (c *Client) handlePreviousMessage(group state.GroupID, previousMessage stat
 		log.Printf("error while requesting message: %s", err.Error())
 	}
 }
+
+func (c *Client) lastMessage(chat Chat) []byte {
+	last, ok := c.lastMessages[chat]
+	if !ok {
+		return nil
+	}
+
+	return last[:]
+}
diff --git a/client/client_test.go b/client/client_test.go
index ecff605..609b0e4 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -18,6 +18,7 @@ import (
 	"github.com/vacp2p/dasy/event"
 	"github.com/vacp2p/dasy/protobuf"
 	mvdsproto "github.com/vacp2p/mvds/protobuf"
+	"github.com/vacp2p/mvds/state"
 )
 
 func TestMain(m *testing.M) {
@@ -27,6 +28,30 @@ func TestMain(m *testing.M) {
 
 // @todo think about turning feed into an interface so we can mock it and ensure its never called when sigs fail
 
+func TestClient_Post(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	node := internal.NewMockDataSyncNode(ctrl)
+	identity, _ := ecdsa.GenerateKey(secp256k1.S256(), rand.Reader)
+
+	client := Client{
+		node:         node,
+		lastMessages: make(map[Chat]state.MessageID),
+		identity:     identity,
+	}
+
+	chat := Chat([32]byte{0x01, 0x2, 0x3, 0x4})
+	msgid := state.MessageID([32]byte{0x01, 0x2, 0x3})
+
+	node.EXPECT().AppendMessage(state.GroupID(chat), gomock.Any()).Return(msgid, nil)
+
+	ret, _ := client.Post(chat, []byte("string"))
+	if msgid != ret {
+		t.Error("returned message ID does not match expected")
+	}
+}
+
 func TestClient_Listen_MessageSentToFeed(t *testing.T) {
 	ctrl := gomock.NewController(t)
 	defer ctrl.Finish()