diff --git a/acme/acme.go b/acme/acme.go
index 3cf7486..9e28b32 100644
--- a/acme/acme.go
+++ b/acme/acme.go
@@ -750,12 +750,16 @@
 }
 
 // popNonce returns a nonce value previously stored with c.addNonce
-// or fetches a fresh one from a URL by issuing a HEAD request.
-// It first tries c.directoryURL() and then the provided url if the former fails.
+// or fetches a fresh one from c.dir.NonceURL.
+// If NonceURL is empty, it first tries c.directoryURL() and, failing that,
+// the provided url.
 func (c *Client) popNonce(ctx context.Context, url string) (string, error) {
 	c.noncesMu.Lock()
 	defer c.noncesMu.Unlock()
 	if len(c.nonces) == 0 {
+		if c.dir != nil && c.dir.NonceURL != "" {
+			return c.fetchNonce(ctx, c.dir.NonceURL)
+		}
 		dirURL := c.directoryURL()
 		v, err := c.fetchNonce(ctx, dirURL)
 		if err != nil && url != dirURL {
diff --git a/acme/rfc8555_test.go b/acme/rfc8555_test.go
index bfb5e53..4a8d9f5 100644
--- a/acme/rfc8555_test.go
+++ b/acme/rfc8555_test.go
@@ -84,3 +84,40 @@
 		t.Error("dir.Meta.ExternalAccountRequired is false")
 	}
 }
+
+func TestRFC_popNonce(t *testing.T) {
+	var count int
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// The Client uses only Directory.NonceURL when specified.
+		// Expect no other URL paths.
+		if r.URL.Path != "/new-nonce" {
+			t.Errorf("r.URL.Path = %q; want /new-nonce", r.URL.Path)
+		}
+		if count > 0 {
+			w.WriteHeader(http.StatusTooManyRequests)
+			return
+		}
+		count++
+		w.Header().Set("Replay-Nonce", "second")
+	}))
+	cl := &Client{
+		DirectoryURL: ts.URL,
+		dir:          &Directory{NonceURL: ts.URL + "/new-nonce"},
+	}
+	cl.addNonce(http.Header{"Replay-Nonce": {"first"}})
+
+	for i, nonce := range []string{"first", "second"} {
+		v, err := cl.popNonce(context.Background(), "")
+		if err != nil {
+			t.Errorf("%d: cl.popNonce: %v", i, err)
+		}
+		if v != nonce {
+			t.Errorf("%d: cl.popNonce = %q; want %q", i, v, nonce)
+		}
+	}
+	// No more nonces and server replies with an error past first nonce fetch.
+	// Expected to fail.
+	if _, err := cl.popNonce(context.Background(), ""); err == nil {
+		t.Error("last cl.popNonce returned nil error")
+	}
+}