diff --git a/api/api.go b/api/api.go
index 7c935f3f..ba7d3d17 100644
--- a/api/api.go
+++ b/api/api.go
@@ -50,7 +50,7 @@ type Authority interface {
 	GetRoots() ([]*x509.Certificate, error)
 	GetFederation() ([]*x509.Certificate, error)
 	Version() authority.Version
-	GenerateCertificateRevocationList(force bool) (string, error)
+	GenerateCertificateRevocationList(force bool) ([]byte, error)
 }
 
 // TimeDuration is an alias of provisioner.TimeDuration
diff --git a/api/crl.go b/api/crl.go
index 50b29d6c..46758777 100644
--- a/api/crl.go
+++ b/api/crl.go
@@ -1,16 +1,24 @@
 package api
 
-import "net/http"
+import (
+	"encoding/pem"
+	"net/http"
+)
 
-// CRL is an HTTP handler that returns the current CRL
+// CRL is an HTTP handler that returns the current CRL in PEM format
 func (h *caHandler) CRL(w http.ResponseWriter, r *http.Request) {
-	crl, err := h.Authority.GenerateCertificateRevocationList(false)
+	crlBytes, err := h.Authority.GenerateCertificateRevocationList(false)
 
 	if err != nil {
 		w.WriteHeader(500)
 		return
 	}
 
+	pemBytes := pem.EncodeToMemory(&pem.Block{
+		Type:  "X509 CRL",
+		Bytes: crlBytes,
+	})
+
 	w.WriteHeader(200)
-	_, err = w.Write([]byte(crl))
+	_, err = w.Write(pemBytes)
 }
diff --git a/authority/tls.go b/authority/tls.go
index d6d6d6d1..d6d80643 100644
--- a/authority/tls.go
+++ b/authority/tls.go
@@ -514,24 +514,24 @@ func (a *Authority) revokeSSH(crt *ssh.Certificate, rci *db.RevokedCertificateIn
 // a new CRL on demand if it has expired (or a CRL does not already exist).
 //
 // force set to true will force regeneration of the CRL regardless of whether it has actually expired
-func (a *Authority) GenerateCertificateRevocationList(force bool) (string, error) {
+func (a *Authority) GenerateCertificateRevocationList(force bool) ([]byte, error) {
 
 	// check for an existing CRL in the database, and return that if its valid
 	crlInfo, err := a.db.GetCRL()
 
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
 	if !force && crlInfo != nil && crlInfo.ExpiresAt.After(time.Now().UTC()) {
-		return crlInfo.PEM, nil
+		return crlInfo.DER, nil
 	}
 
 	// some CAS may not implement the CRLGenerator interface, so check before we proceed
 	caCRLGenerator, ok := a.x509CAService.(casapi.CertificateAuthorityCRLGenerator)
 
 	if !ok {
-		return "", errors.Errorf("CRL Generator not implemented")
+		return nil, errors.Errorf("CRL Generator not implemented")
 	}
 
 	revokedList, err := a.db.GetRevokedCertificates()
@@ -574,28 +574,24 @@ func (a *Authority) GenerateCertificateRevocationList(force bool) (string, error
 
 	certificateRevocationList, err := caCRLGenerator.CreateCertificateRevocationList(&revocationList)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
-	// Quick and dirty PEM encoding
-	// TODO: clean this up
-	pemCRL := fmt.Sprintf("-----BEGIN X509 CRL-----\n%s\n-----END X509 CRL-----\n", base64.StdEncoding.EncodeToString(certificateRevocationList))
-
 	// Create a new db.CertificateRevocationListInfo, which stores the new Number we just generated, the
 	// expiry time, and the byte-encoded CRL - then store it in the DB
 	newCRLInfo := db.CertificateRevocationListInfo{
 		Number:    n,
 		ExpiresAt: revocationList.NextUpdate,
-		PEM:       pemCRL,
+		DER:       certificateRevocationList,
 	}
 
 	err = a.db.StoreCRL(&newCRLInfo)
 	if err != nil {
-		return "", err
+		return nil, err
 	}
 
 	// Finally, return our CRL PEM
-	return pemCRL, nil
+	return certificateRevocationList, nil
 }
 
 // GetTLSCertificate creates a new leaf certificate to be used by the CA HTTPS server.
diff --git a/db/db.go b/db/db.go
index a4c1fa01..534c4000 100644
--- a/db/db.go
+++ b/db/db.go
@@ -114,12 +114,12 @@ type RevokedCertificateInfo struct {
 	ACME          bool
 }
 
-// CertificateRevocationListInfo contains a CRL in PEM and associated metadata to allow a decision on whether
-// to regenerate the CRL or not easier
+// CertificateRevocationListInfo contains a CRL in DER format and associated
+// metadata to allow a decision on whether to regenerate the CRL or not easier
 type CertificateRevocationListInfo struct {
 	Number    int64
 	ExpiresAt time.Time
-	PEM       string
+	DER       []byte
 }
 
 // IsRevoked returns whether or not a certificate with the given identifier
@@ -379,6 +379,18 @@ type MockAuthDB struct {
 	MShutdown             func() error
 }
 
+func (m *MockAuthDB) GetRevokedCertificates() (*[]RevokedCertificateInfo, error) {
+	panic("implement me")
+}
+
+func (m *MockAuthDB) GetCRL() (*CertificateRevocationListInfo, error) {
+	panic("implement me")
+}
+
+func (m *MockAuthDB) StoreCRL(info *CertificateRevocationListInfo) error {
+	panic("implement me")
+}
+
 // IsRevoked mock.
 func (m *MockAuthDB) IsRevoked(sn string) (bool, error) {
 	if m.MIsRevoked != nil {