diff --git a/src/net/http/export_test.go b/src/net/http/export_test.go
index 2c606a45a3..5ff85bc7c8 100644
--- a/src/net/http/export_test.go
+++ b/src/net/http/export_test.go
@@ -33,6 +33,8 @@ var (
 	Export_writeStatusLine            = writeStatusLine
 )
 
+const MaxWriteWaitBeforeConnReuse = maxWriteWaitBeforeConnReuse
+
 func init() {
 	// We only want to pay for this cost during testing.
 	// When not under test, these values are always nil
diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index 4e2dd3beb5..28469f2d82 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -1918,6 +1918,11 @@ func (pc *persistConn) writeLoop() {
 	}
 }
 
+// maxWriteWaitBeforeConnReuse is how long the a Transport RoundTrip
+// will wait to see the Request's Body.Write result after getting a
+// response from the server. See comments in (*persistConn).wroteRequest.
+const maxWriteWaitBeforeConnReuse = 50 * time.Millisecond
+
 // wroteRequest is a check before recycling a connection that the previous write
 // (from writeLoop above) happened and was successful.
 func (pc *persistConn) wroteRequest() bool {
@@ -1940,7 +1945,7 @@ func (pc *persistConn) wroteRequest() bool {
 		select {
 		case err := <-pc.writeErrCh:
 			return err == nil
-		case <-time.After(50 * time.Millisecond):
+		case <-time.After(maxWriteWaitBeforeConnReuse):
 			return false
 		}
 	}
diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index d1efa73cd9..aa8beb9357 100644
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -3050,9 +3050,16 @@ func TestRetryRequestsOnError(t *testing.T) {
 			defer SetRoundTripRetried(nil)
 
 			for i := 0; i < 3; i++ {
+				t0 := time.Now()
 				res, err := c.Do(tc.req())
 				if err != nil {
-					t.Fatalf("i=%d: Do = %v", i, err)
+					if time.Since(t0) < MaxWriteWaitBeforeConnReuse/2 {
+						mu.Lock()
+						got := logbuf.String()
+						mu.Unlock()
+						t.Fatalf("i=%d: Do = %v; log:\n%s", i, err, got)
+					}
+					t.Skipf("connection likely wasn't recycled within %d, interfering with actual test; skipping", MaxWriteWaitBeforeConnReuse)
 				}
 				res.Body.Close()
 			}