diff --git a/runtime/internal/flow/conn/conn.go b/runtime/internal/flow/conn/conn.go
index 64fca19..29b833a 100644
--- a/runtime/internal/flow/conn/conn.go
+++ b/runtime/internal/flow/conn/conn.go
@@ -360,7 +360,13 @@
 func (c *Conn) RTT() time.Duration {
 	defer c.mu.Unlock()
 	c.mu.Lock()
-	return c.hcstate.lastRTT
+	rtt := c.hcstate.lastRTT
+	if !c.hcstate.requestSent.IsZero() {
+		if waitRTT := time.Since(c.hcstate.requestSent); waitRTT > rtt {
+			rtt = waitRTT
+		}
+	}
+	return rtt
 }
 
 func (c *Conn) initializeHealthChecks(ctx *context.T, firstRTT time.Duration) {
@@ -401,6 +407,7 @@
 		c.hcstate.requestTimer.Reset(timeout / 2)
 		c.hcstate.requestDeadline = time.Now().Add(timeout / 2)
 		c.hcstate.lastRTT = time.Since(c.hcstate.requestSent)
+		c.hcstate.requestSent = time.Time{}
 	}
 }
 
diff --git a/runtime/internal/flow/conn/conn_test.go b/runtime/internal/flow/conn/conn_test.go
index 1b65dc7..263f826 100644
--- a/runtime/internal/flow/conn/conn_test.go
+++ b/runtime/internal/flow/conn/conn_test.go
@@ -91,7 +91,6 @@
 	go doWrite(t, df, payload)
 	af := <-flows
 
-	ctx.Infof("%v, %v", df.Conn().RTT(), af.Conn().RTT())
 	if df.Conn().RTT() == 0 {
 		t.Errorf("dialed conn's RTT should be non-zero")
 	}