diff --git a/ocsp_test.go b/ocsp_test.go
index f50a4fe..4c3df27 100644
--- a/ocsp_test.go
+++ b/ocsp_test.go
@@ -1,39 +1,182 @@
 package certmagic
 
 import (
+	"bytes"
 	"context"
+	"crypto"
 	"errors"
+	"io"
+	"net/http"
+	"net/http/httptest"
 	"testing"
+
+	"golang.org/x/crypto/ocsp"
 )
 
-// certWithoutOCSPServer is a minimal self-signed certificate.
-const certWithoutOCSPServer = `-----BEGIN CERTIFICATE-----
-MIIBEDCBtqADAgECAgEBMAoGCCqGSM49BAMCMAAwIhgPMDAwMTAxMDEwMDAwMDBa
-GA8wMDAxMDEwMTAwMDAwMFowADBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABJ0p
-7FKiv9p5rMMzntQeEBesKQnFR4XYFZ/SVlgJHFzd/QZ2sSxW+Mlbz78TTp4DMMIZ
-J0z/Tw2+6fWdvoCYCW2jHTAbMBkGA1UdEQEB/wQPMA2CC2V4YW1wbGUuY29tMAoG
-CCqGSM49BAMCA0kAMEYCIQDMbDvbJ/SXgRoblhBmt80F5iAyuOA0v20x0gpImK01
-oQIhANxdGJPvBaz0wOVBCSpd5jHbPxPxwqKZYJEes6y7eM+I
+const certWithOCSPServer = `-----BEGIN CERTIFICATE-----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 -----END CERTIFICATE-----`
 
-const privateKey = `-----BEGIN EC PRIVATE KEY-----
+const certWithoutOCSPServer = `-----BEGIN CERTIFICATE-----
+MIIBUzCB+aADAgECAgIgADAKBggqhkjOPQQDAjASMRAwDgYDVQQDEwdUZXN0IENB
+MB4XDTIzMDEwMTEyMDAwMFoXDTIzMDIwMTEyMDAwMFowIDEeMBwGA1UEAxMVT0NT
+UCBUZXN0IENlcnRpZmljYXRlMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEih4j
+9uOjfiqifLwt1EkP4mG6Tz9LxgddEeXqsf23lUUIW1fyUg838uXXMKtDYoHdaVt/
+FKCJDIusKlnKt2FU9KMxMC8wDAYDVR0TAQH/BAIwADAfBgNVHSMEGDAWgBT4Sjfm
+xJPgtGvBLh254h0YFnl3sjAKBggqhkjOPQQDAgNJADBGAiEA3rWetLGblfSuNZKf
+5CpZxhj3A0BjEocEh+2P+nAgIdUCIQDIgptabR1qTLQaF2u0hJsEX2IKuIUvYWH3
+6Lb92+zIHg==
+-----END CERTIFICATE-----`
+
+// certKey is the private key for both certWithOCSPServer and
+// certWithoutOCSPServer.
+const certKey = `-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEINnVcgrSNh4HlThWlZpegq14M8G/p9NVDtdVjZrseUGLoAoGCCqGSM49
+AwEHoUQDQgAEih4j9uOjfiqifLwt1EkP4mG6Tz9LxgddEeXqsf23lUUIW1fyUg83
+8uXXMKtDYoHdaVt/FKCJDIusKlnKt2FU9A==
+-----END EC PRIVATE KEY-----`
+
+// caCert is the issuing certificate for certWithOCSPServer and
+// certWithoutOCSPServer.
+const caCert = `-----BEGIN CERTIFICATE-----
+MIIBazCCARGgAwIBAgICEAAwCgYIKoZIzj0EAwIwEjEQMA4GA1UEAxMHVGVzdCBD
+QTAeFw0yMzAxMDExMjAwMDBaFw0yMzAyMDExMjAwMDBaMBIxEDAOBgNVBAMTB1Rl
+c3QgQ0EwWTATBgcqhkjOPQIBBggqhkjOPQMBBwNCAASdKexSor/aeazDM57UHhAX
+rCkJxUeF2BWf0lZYCRxc3f0GdrEsVvjJW8+/E06eAzDCGSdM/08Nvun1nb6AmAlt
+o1cwVTAOBgNVHQ8BAf8EBAMCAQYwEwYDVR0lBAwwCgYIKwYBBQUHAwkwDwYDVR0T
+AQH/BAUwAwEB/zAdBgNVHQ4EFgQU+Eo35sST4LRrwS4dueIdGBZ5d7IwCgYIKoZI
+zj0EAwIDSAAwRQIgGbA39+kETTB/YMLBFoC2fpZe1cDWfFB7TUdfINUqdH4CIQCR
+ByUFC8A+hRNkK5YNH78bgjnKk/88zUQF5ONy4oPGdQ==
+-----END CERTIFICATE-----`
+
+const caKey = `-----BEGIN EC PRIVATE KEY-----
 MHcCAQEEIDJ59ptjq3MzILH4zn5IKoH1sYn+zrUeq2kD8+DD2x+OoAoGCCqGSM49
 AwEHoUQDQgAEnSnsUqK/2nmswzOe1B4QF6wpCcVHhdgVn9JWWAkcXN39BnaxLFb4
 yVvPvxNOngMwwhknTP9PDb7p9Z2+gJgJbQ==
 -----END EC PRIVATE KEY-----`
 
-func TestOCSPServerNotSpecified(t *testing.T) {
-	var config OCSPConfig
+func TestStapleOCSP(t *testing.T) {
+	ctx := context.Background()
 	storage := &FileStorage{Path: t.TempDir()}
 
-	pemCert := []byte(certWithoutOCSPServer)
-	cert, err := makeCertificate(pemCert, []byte(privateKey))
+	t.Run("disabled", func(t *testing.T) {
+		cert := mustMakeCertificate(t, certWithOCSPServer, certKey)
+		config := OCSPConfig{DisableStapling: true}
+		err := stapleOCSP(ctx, config, storage, &cert, nil)
+		if err != nil {
+			t.Error("unexpected error:", err)
+		} else if cert.Certificate.OCSPStaple != nil {
+			t.Error("unexpected OCSP staple")
+		}
+	})
+	t.Run("no OCSP server", func(t *testing.T) {
+		cert := mustMakeCertificate(t, certWithoutOCSPServer, certKey)
+		err := stapleOCSP(ctx, OCSPConfig{}, storage, &cert, nil)
+		if !errors.Is(err, ErrNoOCSPServerSpecified) {
+			t.Error("expected ErrNoOCSPServerSpecified in error", err)
+		}
+	})
+
+	// Start an OCSP responder test server.
+	responses := make(map[string][]byte)
+	responder := startOCSPResponder(t, responses)
+	t.Cleanup(responder.Close)
+
+	ca := mustMakeCertificate(t, caCert, caKey)
+
+	// The certWithOCSPServer certificate has a bogus ocsp.example.com endpoint.
+	// Use the ResponderOverrides option to point to the test server instead.
+	config := OCSPConfig{
+		ResponderOverrides: map[string]string{
+			"ocsp.example.com": responder.URL,
+		},
+	}
+
+	t.Run("ok", func(t *testing.T) {
+		cert := mustMakeCertificate(t, certWithOCSPServer, certKey)
+		tpl := ocsp.Response{
+			Status:       ocsp.Good,
+			SerialNumber: cert.Leaf.SerialNumber,
+		}
+		r, err := ocsp.CreateResponse(
+			ca.Leaf, ca.Leaf, tpl, ca.PrivateKey.(crypto.Signer))
+		if err != nil {
+			t.Fatal("couldn't create OCSP response", err)
+		}
+		responses[cert.Leaf.SerialNumber.String()] = r
+
+		bundle := []byte(certWithOCSPServer + "\n" + caCert)
+		err = stapleOCSP(ctx, config, storage, &cert, bundle)
+		if err != nil {
+			t.Error("unexpected error:", err)
+		} else if !bytes.Equal(cert.Certificate.OCSPStaple, r) {
+			t.Error("expected OCSP response to be stapled to certificate")
+		}
+	})
+	t.Run("revoked", func(t *testing.T) {
+		cert := mustMakeCertificate(t, certWithOCSPServer, certKey)
+		tpl := ocsp.Response{
+			Status:       ocsp.Revoked,
+			SerialNumber: cert.Leaf.SerialNumber,
+		}
+		r, err := ocsp.CreateResponse(
+			ca.Leaf, ca.Leaf, tpl, ca.PrivateKey.(crypto.Signer))
+		if err != nil {
+			t.Fatal("couldn't create OCSP response", err)
+		}
+		responses[cert.Leaf.SerialNumber.String()] = r
+
+		bundle := []byte(certWithOCSPServer + "\n" + caCert)
+		err = stapleOCSP(ctx, config, storage, &cert, bundle)
+		if err != nil {
+			t.Error("unexpected error:", err)
+		} else if cert.Certificate.OCSPStaple != nil {
+			t.Error("revoked OCSP response should not be stapled")
+		}
+	})
+	t.Run("no issuing cert", func(t *testing.T) {
+		cert := mustMakeCertificate(t, certWithOCSPServer, certKey)
+		err := stapleOCSP(ctx, config, storage, &cert, nil)
+		expected := "no OCSP stapling for [ocsp test certificate]: " +
+			"no URL to issuing certificate"
+		if err == nil || err.Error() != expected {
+			t.Errorf("expected error %q but got %q", expected, err)
+		}
+	})
+}
+
+func mustMakeCertificate(t *testing.T, cert, key string) Certificate {
+	t.Helper()
+	c, err := makeCertificate([]byte(cert), []byte(key))
 	if err != nil {
 		t.Fatal("couldn't make certificate:", err)
 	}
-
-	err = stapleOCSP(context.Background(), config, storage, &cert, pemCert)
-	if !errors.Is(err, ErrNoOCSPServerSpecified) {
-		t.Error("expected ErrOCSPServerNotSpecified in error", err)
-	}
+	return c
+}
+
+func startOCSPResponder(
+	t *testing.T, responses map[string][]byte,
+) *httptest.Server {
+	h := func(w http.ResponseWriter, r *http.Request) {
+		ct := r.Header.Get("Content-Type")
+		if ct != "application/ocsp-request" {
+			t.Errorf("unexpected request Content-Type %q", ct)
+		}
+		b, _ := io.ReadAll(r.Body)
+		request, err := ocsp.ParseRequest(b)
+		if err != nil {
+			t.Fatal(err)
+		}
+		w.Header().Set("Content-Type", "application/ocsp-response")
+		w.Write(responses[request.SerialNumber.String()])
+	}
+	return httptest.NewServer(http.HandlerFunc(h))
 }