diff --git a/jsonfxns.go b/jsonfxns.go
index 2d336259..555f612c 100644
--- a/jsonfxns.go
+++ b/jsonfxns.go
@@ -14,9 +14,9 @@ import (
 )
 
 // MarshallAndSend takes the reply structure, marshalls it to json, and
-// sends it back to the http writer, returning a log message and an error if
-// there is one.
-func MarshallAndSend(rawReply Reply, w http.ResponseWriter) (string, error) {
+// sends it back to the io.Writer (most likely an http.ResponseWriter).
+// returning a log message and an error if there is one.
+func MarshallAndSend(rawReply Reply, w io.Writer) (string, error) {
 	finalReply, err := json.Marshal(rawReply)
 	if err != nil {
 		msg := fmt.Sprintf("[RPCS] Error Marshalling reply: %v", err)
diff --git a/jsonfxns_test.go b/jsonfxns_test.go
new file mode 100644
index 00000000..5f1b316a
--- /dev/null
+++ b/jsonfxns_test.go
@@ -0,0 +1,55 @@
+// Copyright (c) 2013 Conformal Systems LLC.
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcjson_test
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/conformal/btcjson"
+	"testing"
+)
+
+// TestMarshallAndSend tests the MarshallAndSend function to make sure it can
+// create a json message to write to the io.Writerr and to make sure
+// it fails properly in cases where it cannot generate json.
+func TestMarshallAndSend(t *testing.T) {
+	jsonError := btcjson.Error{
+		Code:    -32700,
+		Message: "Parse error",
+	}
+	// json.Marshal cannot handle channels so this is a good way to get a
+	// marshal failure.
+	badRes := make(chan interface{})
+	rawReply := btcjson.Reply{
+		Result: badRes,
+		Error:  &jsonError,
+		Id:     nil,
+	}
+	var w bytes.Buffer
+
+	msg, err := btcjson.MarshallAndSend(rawReply, &w)
+	if fmt.Sprintf("%s", err) != "json: unsupported type: chan interface {}" {
+		t.Error("Should not be able to unmarshall channel")
+	}
+
+	// Use something simple so we can compare the reply.
+	rawReply = btcjson.Reply{
+		Result: nil,
+		Error:  nil,
+		Id:     nil,
+	}
+
+	msg, err = btcjson.MarshallAndSend(rawReply, &w)
+	if msg != "[RPCS] reply: {<nil> <nil> <nil>}" {
+		t.Error("Incorrect reply:", msg)
+	}
+
+	expBuf := "{\"result\":null,\"error\":null,\"id\":null}\n"
+
+	if w.String() != expBuf {
+		t.Error("Incorrect data in buffer:", w.String())
+	}
+	return
+}
diff --git a/test_coverage.txt b/test_coverage.txt
index 382d31d6..bdbebbc3 100644
--- a/test_coverage.txt
+++ b/test_coverage.txt
@@ -1,10 +1,10 @@
 
-github.com/conformal/btcjson/jsonapi.go	 JsonCreateMessage	 100.00% (310/310)
-github.com/conformal/btcjson/jsonfxns.go JsonGetRaw		 100.00% (6/6)
-github.com/conformal/btcjson/jsonapi.go	 jsonWithArgs		 100.00% (5/5)
-github.com/conformal/btcjson/jsonfxns.go jsonRpcSend		 100.00% (4/4)
-github.com/conformal/btcjson/jsonapi.go	 JsonRpcCommand		 66.67% (18/27)
-github.com/conformal/btcjson/jsonapi.go	 readResultCmd		 40.00% (20/50)
-github.com/conformal/btcjson/jsonfxns.go JsonMarshallAndSend	 0.00% (0/7)
-github.com/conformal/btcjson		 -------------------	 88.75% (363/409)
+github.com/conformal/btcjson/jsonapi.go	 CreateMessage	 100.00% (310/310)
+github.com/conformal/btcjson/jsonfxns.go MarshallAndSend 100.00% (7/7)
+github.com/conformal/btcjson/jsonfxns.go GetRaw		 100.00% (6/6)
+github.com/conformal/btcjson/jsonapi.go	 jsonWithArgs	 100.00% (5/5)
+github.com/conformal/btcjson/jsonfxns.go jsonRpcSend	 100.00% (4/4)
+github.com/conformal/btcjson/jsonapi.go	 RpcCommand	 66.67% (18/27)
+github.com/conformal/btcjson/jsonapi.go	 readResultCmd	 40.00% (20/50)
+github.com/conformal/btcjson		 --------------- 90.46% (370/409)