diff --git a/key_agreement.go b/key_agreement.go
index b9f86d2..0e6a7c2 100644
--- a/key_agreement.go
+++ b/key_agreement.go
@@ -46,7 +46,7 @@ func (ka rsaKeyAgreement) processClientKeyExchange(config *Config, cert *Certifi
 	if !ok {
 		return nil, errors.New("tls: certificate private key does not implement crypto.Decrypter")
 	}
-	// Perform contant time RSA PKCS#1 v1.5 decryption
+	// Perform constant time RSA PKCS#1 v1.5 decryption
 	preMasterSecret, err := priv.Decrypt(config.rand(), ciphertext, &rsa.PKCS1v15DecryptOptions{SessionKeyLen: 48})
 	if err != nil {
 		return nil, err