diff --git a/src/crypto/tls/alert.go b/src/crypto/tls/alert.go
index 3de4834..9cf9922 100644
--- a/src/crypto/tls/alert.go
+++ b/src/crypto/tls/alert.go
@@ -69,9 +69,9 @@
 func (e alert) String() string {
 	s, ok := alertText[e]
 	if ok {
-		return s
+		return "tls: " + s
 	}
-	return "alert(" + strconv.Itoa(int(e)) + ")"
+	return "tls: alert(" + strconv.Itoa(int(e)) + ")"
 }
 
 func (e alert) Error() string {
diff --git a/src/crypto/tls/common.go b/src/crypto/tls/common.go
index b3399b0..33d585c 100644
--- a/src/crypto/tls/common.go
+++ b/src/crypto/tls/common.go
@@ -516,7 +516,7 @@
 	}
 
 	if len(c.Certificates) == 0 {
-		return nil, errors.New("crypto/tls: no certificates configured")
+		return nil, errors.New("tls: no certificates configured")
 	}
 
 	if len(c.Certificates) == 1 || c.NameToCertificate == nil {
diff --git a/src/crypto/tls/conn.go b/src/crypto/tls/conn.go
index 2b1875d..8c05b15 100644
--- a/src/crypto/tls/conn.go
+++ b/src/crypto/tls/conn.go
@@ -928,7 +928,7 @@
 	return m, nil
 }
 
-var errClosed = errors.New("crypto/tls: use of closed connection")
+var errClosed = errors.New("tls: use of closed connection")
 
 // Write writes data to the connection.
 func (c *Conn) Write(b []byte) (int, error) {
diff --git a/src/crypto/tls/handshake_client.go b/src/crypto/tls/handshake_client.go
index 9517320..75e8402 100644
--- a/src/crypto/tls/handshake_client.go
+++ b/src/crypto/tls/handshake_client.go
@@ -533,17 +533,17 @@
 
 	if !clientDidNPN && serverHasNPN {
 		c.sendAlert(alertHandshakeFailure)
-		return false, errors.New("server advertised unrequested NPN extension")
+		return false, errors.New("tls: server advertised unrequested NPN extension")
 	}
 
 	if !clientDidALPN && serverHasALPN {
 		c.sendAlert(alertHandshakeFailure)
-		return false, errors.New("server advertised unrequested ALPN extension")
+		return false, errors.New("tls: server advertised unrequested ALPN extension")
 	}
 
 	if serverHasNPN && serverHasALPN {
 		c.sendAlert(alertHandshakeFailure)
-		return false, errors.New("server advertised both NPN and ALPN extensions")
+		return false, errors.New("tls: server advertised both NPN and ALPN extensions")
 	}
 
 	if serverHasALPN {
diff --git a/src/crypto/tls/handshake_server.go b/src/crypto/tls/handshake_server.go
index a6cafd3..70f4374 100644
--- a/src/crypto/tls/handshake_server.go
+++ b/src/crypto/tls/handshake_server.go
@@ -209,7 +209,7 @@
 			hs.rsaSignOk = true
 		default:
 			c.sendAlert(alertInternalError)
-			return false, fmt.Errorf("crypto/tls: unsupported signing key type (%T)", priv.Public())
+			return false, fmt.Errorf("tls: unsupported signing key type (%T)", priv.Public())
 		}
 	}
 	if priv, ok := hs.cert.PrivateKey.(crypto.Decrypter); ok {
@@ -218,7 +218,7 @@
 			hs.rsaDecryptOk = true
 		default:
 			c.sendAlert(alertInternalError)
-			return false, fmt.Errorf("crypto/tls: unsupported decryption key type (%T)", priv.Public())
+			return false, fmt.Errorf("tls: unsupported decryption key type (%T)", priv.Public())
 		}
 	}
 
@@ -514,7 +514,7 @@
 		switch key := pub.(type) {
 		case *ecdsa.PublicKey:
 			if signatureAndHash.signature != signatureECDSA {
-				err = errors.New("bad signature type for client's ECDSA certificate")
+				err = errors.New("tls: bad signature type for client's ECDSA certificate")
 				break
 			}
 			ecdsaSig := new(ecdsaSignature)
@@ -522,7 +522,7 @@
 				break
 			}
 			if ecdsaSig.R.Sign() <= 0 || ecdsaSig.S.Sign() <= 0 {
-				err = errors.New("ECDSA signature contained zero or negative values")
+				err = errors.New("tls: ECDSA signature contained zero or negative values")
 				break
 			}
 			var digest []byte
@@ -530,11 +530,11 @@
 				break
 			}
 			if !ecdsa.Verify(key, digest, ecdsaSig.R, ecdsaSig.S) {
-				err = errors.New("ECDSA verification failure")
+				err = errors.New("tls: ECDSA verification failure")
 			}
 		case *rsa.PublicKey:
 			if signatureAndHash.signature != signatureRSA {
-				err = errors.New("bad signature type for client's RSA certificate")
+				err = errors.New("tls: bad signature type for client's RSA certificate")
 				break
 			}
 			var digest []byte
diff --git a/src/crypto/tls/key_agreement.go b/src/crypto/tls/key_agreement.go
index 3326894..467efb2 100644
--- a/src/crypto/tls/key_agreement.go
+++ b/src/crypto/tls/key_agreement.go
@@ -242,19 +242,19 @@
 	case signatureECDSA:
 		_, ok := priv.Public().(*ecdsa.PublicKey)
 		if !ok {
-			return nil, errors.New("ECDHE ECDSA requires an ECDSA server key")
+			return nil, errors.New("tls: ECDHE ECDSA requires an ECDSA server key")
 		}
 	case signatureRSA:
 		_, ok := priv.Public().(*rsa.PublicKey)
 		if !ok {
-			return nil, errors.New("ECDHE RSA requires a RSA server key")
+			return nil, errors.New("tls: ECDHE RSA requires a RSA server key")
 		}
 	default:
-		return nil, errors.New("unknown ECDHE signature algorithm")
+		return nil, errors.New("tls: unknown ECDHE signature algorithm")
 	}
 	sig, err = priv.Sign(config.rand(), digest, hashFunc)
 	if err != nil {
-		return nil, errors.New("failed to sign ECDHE parameters: " + err.Error())
+		return nil, errors.New("tls: failed to sign ECDHE parameters: " + err.Error())
 	}
 
 	skx := new(serverKeyExchangeMsg)
@@ -354,28 +354,28 @@
 	case signatureECDSA:
 		pubKey, ok := cert.PublicKey.(*ecdsa.PublicKey)
 		if !ok {
-			return errors.New("ECDHE ECDSA requires a ECDSA server public key")
+			return errors.New("tls: ECDHE ECDSA requires a ECDSA server public key")
 		}
 		ecdsaSig := new(ecdsaSignature)
 		if _, err := asn1.Unmarshal(sig, ecdsaSig); err != nil {
 			return err
 		}
 		if ecdsaSig.R.Sign() <= 0 || ecdsaSig.S.Sign() <= 0 {
-			return errors.New("ECDSA signature contained zero or negative values")
+			return errors.New("tls: ECDSA signature contained zero or negative values")
 		}
 		if !ecdsa.Verify(pubKey, digest, ecdsaSig.R, ecdsaSig.S) {
-			return errors.New("ECDSA verification failure")
+			return errors.New("tls: ECDSA verification failure")
 		}
 	case signatureRSA:
 		pubKey, ok := cert.PublicKey.(*rsa.PublicKey)
 		if !ok {
-			return errors.New("ECDHE RSA requires a RSA server public key")
+			return errors.New("tls: ECDHE RSA requires a RSA server public key")
 		}
 		if err := rsa.VerifyPKCS1v15(pubKey, hashFunc, digest, sig); err != nil {
 			return err
 		}
 	default:
-		return errors.New("unknown ECDHE signature algorithm")
+		return errors.New("tls: unknown ECDHE signature algorithm")
 	}
 
 	return nil
@@ -383,7 +383,7 @@
 
 func (ka *ecdheKeyAgreement) generateClientKeyExchange(config *Config, clientHello *clientHelloMsg, cert *x509.Certificate) ([]byte, *clientKeyExchangeMsg, error) {
 	if ka.curve == nil {
-		return nil, nil, errors.New("missing ServerKeyExchange message")
+		return nil, nil, errors.New("tls: missing ServerKeyExchange message")
 	}
 	priv, mx, my, err := elliptic.GenerateKey(ka.curve, config.rand())
 	if err != nil {
diff --git a/src/crypto/tls/tls.go b/src/crypto/tls/tls.go
index bfe331d..0be0b42 100644
--- a/src/crypto/tls/tls.go
+++ b/src/crypto/tls/tls.go
@@ -209,12 +209,12 @@
 
 	if len(cert.Certificate) == 0 {
 		if len(skippedBlockTypes) == 0 {
-			return fail(errors.New("crypto/tls: failed to find any PEM data in certificate input"))
+			return fail(errors.New("tls: failed to find any PEM data in certificate input"))
 		}
 		if len(skippedBlockTypes) == 1 && strings.HasSuffix(skippedBlockTypes[0], "PRIVATE KEY") {
-			return fail(errors.New("crypto/tls: failed to find certificate PEM data in certificate input, but did find a private key; PEM inputs may have been switched"))
+			return fail(errors.New("tls: failed to find certificate PEM data in certificate input, but did find a private key; PEM inputs may have been switched"))
 		}
-		return fail(fmt.Errorf("crypto/tls: failed to find \"CERTIFICATE\" PEM block in certificate input after skipping PEM blocks of the following types: %v", skippedBlockTypes))
+		return fail(fmt.Errorf("tls: failed to find \"CERTIFICATE\" PEM block in certificate input after skipping PEM blocks of the following types: %v", skippedBlockTypes))
 	}
 
 	skippedBlockTypes = skippedBlockTypes[:0]
@@ -223,12 +223,12 @@
 		keyDERBlock, keyPEMBlock = pem.Decode(keyPEMBlock)
 		if keyDERBlock == nil {
 			if len(skippedBlockTypes) == 0 {
-				return fail(errors.New("crypto/tls: failed to find any PEM data in key input"))
+				return fail(errors.New("tls: failed to find any PEM data in key input"))
 			}
 			if len(skippedBlockTypes) == 1 && skippedBlockTypes[0] == "CERTIFICATE" {
-				return fail(errors.New("crypto/tls: found a certificate rather than a key in the PEM for the private key"))
+				return fail(errors.New("tls: found a certificate rather than a key in the PEM for the private key"))
 			}
-			return fail(fmt.Errorf("crypto/tls: failed to find PEM block with type ending in \"PRIVATE KEY\" in key input after skipping PEM blocks of the following types: %v", skippedBlockTypes))
+			return fail(fmt.Errorf("tls: failed to find PEM block with type ending in \"PRIVATE KEY\" in key input after skipping PEM blocks of the following types: %v", skippedBlockTypes))
 		}
 		if keyDERBlock.Type == "PRIVATE KEY" || strings.HasSuffix(keyDERBlock.Type, " PRIVATE KEY") {
 			break
@@ -253,21 +253,21 @@
 	case *rsa.PublicKey:
 		priv, ok := cert.PrivateKey.(*rsa.PrivateKey)
 		if !ok {
-			return fail(errors.New("crypto/tls: private key type does not match public key type"))
+			return fail(errors.New("tls: private key type does not match public key type"))
 		}
 		if pub.N.Cmp(priv.N) != 0 {
-			return fail(errors.New("crypto/tls: private key does not match public key"))
+			return fail(errors.New("tls: private key does not match public key"))
 		}
 	case *ecdsa.PublicKey:
 		priv, ok := cert.PrivateKey.(*ecdsa.PrivateKey)
 		if !ok {
-			return fail(errors.New("crypto/tls: private key type does not match public key type"))
+			return fail(errors.New("tls: private key type does not match public key type"))
 		}
 		if pub.X.Cmp(priv.X) != 0 || pub.Y.Cmp(priv.Y) != 0 {
-			return fail(errors.New("crypto/tls: private key does not match public key"))
+			return fail(errors.New("tls: private key does not match public key"))
 		}
 	default:
-		return fail(errors.New("crypto/tls: unknown public key algorithm"))
+		return fail(errors.New("tls: unknown public key algorithm"))
 	}
 
 	return cert, nil
@@ -285,12 +285,12 @@
 		case *rsa.PrivateKey, *ecdsa.PrivateKey:
 			return key, nil
 		default:
-			return nil, errors.New("crypto/tls: found unknown private key type in PKCS#8 wrapping")
+			return nil, errors.New("tls: found unknown private key type in PKCS#8 wrapping")
 		}
 	}
 	if key, err := x509.ParseECPrivateKey(der); err == nil {
 		return key, nil
 	}
 
-	return nil, errors.New("crypto/tls: failed to parse private key")
+	return nil, errors.New("tls: failed to parse private key")
 }