diff --git a/lib/internal/crypto/diffiehellman.js b/lib/internal/crypto/diffiehellman.js
index 3f52e78d7a3036..59bbf8ff71233c 100644
--- a/lib/internal/crypto/diffiehellman.js
+++ b/lib/internal/crypto/diffiehellman.js
@@ -51,7 +51,6 @@ const {
 
 const {
   getArrayBufferOrView,
-  getDefaultEncoding,
   jobPromise,
   toBuf,
   kHandle,
@@ -97,10 +96,6 @@ function DiffieHellman(sizeOrKey, keyEncoding, generator, genEncoding) {
     keyEncoding = false;
   }
 
-  const encoding = getDefaultEncoding();
-  keyEncoding = keyEncoding || encoding;
-  genEncoding = genEncoding || encoding;
-
   if (typeof sizeOrKey !== 'number')
     sizeOrKey = toBuf(sizeOrKey, keyEncoding);
 
@@ -148,7 +143,6 @@ DiffieHellmanGroup.prototype.generateKeys =
 
 function dhGenerateKeys(encoding) {
   const keys = this[kHandle].generateKeys();
-  encoding = encoding || getDefaultEncoding();
   return encode(keys, encoding);
 }
 
@@ -158,9 +152,6 @@ DiffieHellmanGroup.prototype.computeSecret =
     dhComputeSecret;
 
 function dhComputeSecret(key, inEnc, outEnc) {
-  const encoding = getDefaultEncoding();
-  inEnc = inEnc || encoding;
-  outEnc = outEnc || encoding;
   key = getArrayBufferOrView(key, 'key', inEnc);
   const ret = this[kHandle].computeSecret(key);
   if (typeof ret === 'string')
@@ -175,7 +166,6 @@ DiffieHellmanGroup.prototype.getPrime =
 
 function dhGetPrime(encoding) {
   const prime = this[kHandle].getPrime();
-  encoding = encoding || getDefaultEncoding();
   return encode(prime, encoding);
 }
 
@@ -186,7 +176,6 @@ DiffieHellmanGroup.prototype.getGenerator =
 
 function dhGetGenerator(encoding) {
   const generator = this[kHandle].getGenerator();
-  encoding = encoding || getDefaultEncoding();
   return encode(generator, encoding);
 }
 
@@ -197,7 +186,6 @@ DiffieHellmanGroup.prototype.getPublicKey =
 
 function dhGetPublicKey(encoding) {
   const key = this[kHandle].getPublicKey();
-  encoding = encoding || getDefaultEncoding();
   return encode(key, encoding);
 }
 
@@ -208,13 +196,11 @@ DiffieHellmanGroup.prototype.getPrivateKey =
 
 function dhGetPrivateKey(encoding) {
   const key = this[kHandle].getPrivateKey();
-  encoding = encoding || getDefaultEncoding();
   return encode(key, encoding);
 }
 
 
 DiffieHellman.prototype.setPublicKey = function setPublicKey(key, encoding) {
-  encoding = encoding || getDefaultEncoding();
   key = getArrayBufferOrView(key, 'key', encoding);
   this[kHandle].setPublicKey(key);
   return this;
@@ -222,7 +208,6 @@ DiffieHellman.prototype.setPublicKey = function setPublicKey(key, encoding) {
 
 
 DiffieHellman.prototype.setPrivateKey = function setPrivateKey(key, encoding) {
-  encoding = encoding || getDefaultEncoding();
   key = getArrayBufferOrView(key, 'key', encoding);
   this[kHandle].setPrivateKey(key);
   return this;
@@ -251,15 +236,12 @@ ECDH.prototype.generateKeys = function generateKeys(encoding, format) {
 ECDH.prototype.getPublicKey = function getPublicKey(encoding, format) {
   const f = getFormat(format);
   const key = this[kHandle].getPublicKey(f);
-  encoding = encoding || getDefaultEncoding();
   return encode(key, encoding);
 };
 
 ECDH.convertKey = function convertKey(key, curve, inEnc, outEnc, format) {
   validateString(curve, 'curve');
-  const encoding = inEnc || getDefaultEncoding();
-  key = getArrayBufferOrView(key, 'key', encoding);
-  outEnc = outEnc || encoding;
+  key = getArrayBufferOrView(key, 'key', inEnc);
   const f = getFormat(format);
   const convertedKey = _ECDHConvertKey(key, curve, f);
   return encode(convertedKey, outEnc);