diff --git a/diagnostics/diagnostics.go b/diagnostics/diagnostics.go
index c45afdf25..eb761e6c9 100644
--- a/diagnostics/diagnostics.go
+++ b/diagnostics/diagnostics.go
@@ -96,7 +96,7 @@ func (d *Diagnostics) schedule() {
 // Flush sends the current metrics.
 func (d *Diagnostics) Flush() error {
 	d.mu.Lock()
-	d.metrics["uptime"] = (time.Now().Unix() - d.startTime)
+	d.metrics["Uptime"] = (time.Now().Unix() - d.startTime)
 	buf, _ := d.Encode()
 	d.mu.Unlock()
 
diff --git a/diagnostics/diagnostics_test.go b/diagnostics/diagnostics_test.go
index 8e3a7cce4..7ac4906d4 100644
--- a/diagnostics/diagnostics_test.go
+++ b/diagnostics/diagnostics_test.go
@@ -49,7 +49,7 @@ func TestDiagnosticsClient(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	output2 := []byte(`{"gg":10,"ss":"ss","uptime":0}`)
+	output2 := []byte(`{"gg":10,"ss":"ss","Uptime":0}`)
 	if eq, err = compareJSON(data, output2); err != nil {
 		t.Fatal(err)
 	}