diff --git a/ddtrace/tracer/log.go b/ddtrace/tracer/log.go
index 7e494319f0..709c4a3ed1 100644
--- a/ddtrace/tracer/log.go
+++ b/ddtrace/tracer/log.go
@@ -6,6 +6,7 @@
 package tracer
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
 	"math"
@@ -51,10 +52,12 @@ type startupInfo struct {
 // If the endpoint is not reachable, checkEndpoint returns an error
 // explaining why.
 func checkEndpoint(endpoint string) error {
-	req, err := http.NewRequest("POST", endpoint, nil)
+	req, err := http.NewRequest("POST", endpoint, bytes.NewReader([]byte{0x90}))
 	if err != nil {
 		return fmt.Errorf("cannot create http request: %v", err)
 	}
+	req.Header.Set(traceCountHeader, "0")
+	req.Header.Set("Content-Type", "application/msgpack")
 	_, err = defaultClient.Do(req)
 	if err != nil {
 		return err
diff --git a/ddtrace/tracer/transport.go b/ddtrace/tracer/transport.go
index 7fa506e468..ce459e6edf 100644
--- a/ddtrace/tracer/transport.go
+++ b/ddtrace/tracer/transport.go
@@ -58,9 +58,9 @@ type transport interface {
 
 // newTransport returns a new Transport implementation that sends traces to a
 // trace agent running on the given hostname and port, using a given
-// http.RoundTripper. If the zero values for hostname and port are provided,
+// *http.Client. If the zero values for hostname and port are provided,
 // the default values will be used ("localhost" for hostname, and "8126" for
-// port). If roundTripper is nil, a default is used.
+// port). If client is nil, a default is used.
 //
 // In general, using this method is only necessary if you have a trace agent
 // running on a non-default port, if it's located on another machine, or when