diff --git a/btcjson/cmdparse_test.go b/btcjson/cmdparse_test.go
index 7c13a0bb..dd951dcb 100644
--- a/btcjson/cmdparse_test.go
+++ b/btcjson/cmdparse_test.go
@@ -201,7 +201,7 @@ func TestAssignFieldErrors(t *testing.T) {
 	}{
 		{
 			name: "general incompatible int -> string",
-			dest: string(0),
+			dest: "\x00",
 			src:  int(0),
 			err:  btcjson.Error{ErrorCode: btcjson.ErrInvalidType},
 		},
diff --git a/wire/message.go b/wire/message.go
index e9376477..fe45a11f 100644
--- a/wire/message.go
+++ b/wire/message.go
@@ -213,7 +213,7 @@ func readMessageHeader(r io.Reader) (int, *messageHeader, error) {
 	readElements(hr, &hdr.magic, &command, &hdr.length, &hdr.checksum)
 
 	// Strip trailing zeros from command string.
-	hdr.command = string(bytes.TrimRight(command[:], string(0)))
+	hdr.command = string(bytes.TrimRight(command[:], "\x00"))
 
 	return n, &hdr, nil
 }