diff --git a/openpgp/packet/packet.go b/openpgp/packet/packet.go
index 625bb5a..5af64c5 100644
--- a/openpgp/packet/packet.go
+++ b/openpgp/packet/packet.go
@@ -404,14 +404,16 @@ const (
 type PublicKeyAlgorithm uint8
 
 const (
-	PubKeyAlgoRSA            PublicKeyAlgorithm = 1
-	PubKeyAlgoRSAEncryptOnly PublicKeyAlgorithm = 2
-	PubKeyAlgoRSASignOnly    PublicKeyAlgorithm = 3
-	PubKeyAlgoElGamal        PublicKeyAlgorithm = 16
-	PubKeyAlgoDSA            PublicKeyAlgorithm = 17
+	PubKeyAlgoRSA     PublicKeyAlgorithm = 1
+	PubKeyAlgoElGamal PublicKeyAlgorithm = 16
+	PubKeyAlgoDSA     PublicKeyAlgorithm = 17
 	// RFC 6637, Section 5.
 	PubKeyAlgoECDH  PublicKeyAlgorithm = 18
 	PubKeyAlgoECDSA PublicKeyAlgorithm = 19
+
+	// Deprecated in RFC 4880, Section 13.5. Use key flags instead.
+	PubKeyAlgoRSAEncryptOnly PublicKeyAlgorithm = 2
+	PubKeyAlgoRSASignOnly    PublicKeyAlgorithm = 3
 )
 
 // CanEncrypt returns true if it's possible to encrypt a message to a public
diff --git a/openpgp/packet/private_key.go b/openpgp/packet/private_key.go
index 87fc461..bd31cce 100644
--- a/openpgp/packet/private_key.go
+++ b/openpgp/packet/private_key.go
@@ -64,7 +64,7 @@ func NewECDSAPrivateKey(currentTime time.Time, priv *ecdsa.PrivateKey) *PrivateK
 	return pk
 }
 
-// NewSignerPrivateKey creates a sign-only PrivateKey from a crypto.Signer that
+// NewSignerPrivateKey creates a PrivateKey from a crypto.Signer that
 // implements RSA or ECDSA.
 func NewSignerPrivateKey(currentTime time.Time, signer crypto.Signer) *PrivateKey {
 	pk := new(PrivateKey)
@@ -73,10 +73,8 @@ func NewSignerPrivateKey(currentTime time.Time, signer crypto.Signer) *PrivateKe
 	switch pubkey := signer.Public().(type) {
 	case *rsa.PublicKey:
 		pk.PublicKey = *NewRSAPublicKey(currentTime, pubkey)
-		pk.PubKeyAlgo = PubKeyAlgoRSASignOnly
 	case rsa.PublicKey:
 		pk.PublicKey = *NewRSAPublicKey(currentTime, &pubkey)
-		pk.PubKeyAlgo = PubKeyAlgoRSASignOnly
 	case *ecdsa.PublicKey:
 		pk.PublicKey = *NewECDSAPublicKey(currentTime, pubkey)
 	case ecdsa.PublicKey:
diff --git a/openpgp/packet/private_key_test.go b/openpgp/packet/private_key_test.go
index 794d746..cc08b48 100644
--- a/openpgp/packet/private_key_test.go
+++ b/openpgp/packet/private_key_test.go
@@ -172,12 +172,8 @@ func TestRSASignerPrivateKey(t *testing.T) {
 
 	priv := NewSignerPrivateKey(time.Now(), &rsaSigner{rsaPriv})
 
-	if priv.PubKeyAlgo != PubKeyAlgoRSASignOnly {
-		t.Fatal("NewSignerPrivateKey should have made a sign-only RSA private key")
-	}
-
 	sig := &Signature{
-		PubKeyAlgo: PubKeyAlgoRSASignOnly,
+		PubKeyAlgo: PubKeyAlgoRSA,
 		Hash:       crypto.SHA256,
 	}
 	msg := []byte("Hello World!")