diff --git a/acme/jws.go b/acme/jws.go
index 74a41867..96f7ae9e 100644
--- a/acme/jws.go
+++ b/acme/jws.go
@@ -6,15 +6,13 @@ import (
 	"crypto/rsa"
 	"fmt"
 	"net/http"
-	"sync"
 
 	"github.com/letsencrypt/go-jose"
 )
 
 type jws struct {
-	privKey    *rsa.PrivateKey
-	nonces     []string
-	nonceMutex sync.Mutex
+	privKey *rsa.PrivateKey
+	nonces  []string
 }
 
 func keyAsJWK(key *ecdsa.PublicKey) jose.JsonWebKey {
@@ -26,9 +24,11 @@ func keyAsJWK(key *ecdsa.PublicKey) jose.JsonWebKey {
 
 // Posts a JWS signed message to the specified URL
 func (j *jws) post(url string, content []byte) (*http.Response, error) {
-	err := j.getNonce(url)
-	if err != nil {
-		return nil, fmt.Errorf("Could not get a nonce for request: %s\n\t\tError: %v", url, err)
+	if len(j.nonces) == 0 {
+		err := j.getNonce(url)
+		if err != nil {
+			return nil, fmt.Errorf("Could not get a nonce for request: %s\n\t\tError: %v", url, err)
+		}
 	}
 
 	signedContent, err := j.signContent(content)
@@ -66,20 +66,11 @@ func (j *jws) getNonceFromResponse(resp *http.Response) error {
 		return fmt.Errorf("Server did not respond with a proper nonce header.")
 	}
 
-	j.nonceMutex.Lock()
 	j.nonces = append(j.nonces, nonce)
-	j.nonceMutex.Unlock()
 	return nil
 }
 
 func (j *jws) getNonce(url string) error {
-	j.nonceMutex.Lock()
-	if len(j.nonces) > 0 {
-		j.nonceMutex.Unlock()
-		return nil
-	}
-	j.nonceMutex.Unlock()
-
 	resp, err := http.Head(url)
 	if err != nil {
 		return err
@@ -89,9 +80,6 @@ func (j *jws) getNonce(url string) error {
 }
 
 func (j *jws) consumeNonce() string {
-	j.nonceMutex.Lock()
-	defer j.nonceMutex.Unlock()
-
 	nonce := ""
 	if len(j.nonces) == 0 {
 		return nonce