diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index 1a532ae66f1de2..88b905f7f990d7 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -5158,10 +5158,7 @@ void DiffieHellman::DiffieHellmanGroup(
   Environment* env = Environment::GetCurrent(args);
   DiffieHellman* diffieHellman = new DiffieHellman(env, args.This());
 
-  if (args.Length() != 1) {
-    return THROW_ERR_MISSING_ARGS(env, "Group name argument is mandatory");
-  }
-
+  CHECK_EQ(args.Length(), 1);
   THROW_AND_RETURN_IF_NOT_STRING(env, args[0], "Group name");
 
   bool initialized = false;
@@ -5169,7 +5166,7 @@ void DiffieHellman::DiffieHellmanGroup(
   const node::Utf8Value group_name(env->isolate(), args[0]);
   const modp_group* group = FindDiffieHellmanGroup(*group_name);
   if (group == nullptr)
-    return env->ThrowError("Unknown group");
+    return THROW_ERR_CRYPTO_UNKNOWN_DH_GROUP(env, "Unknown group");
 
   initialized = diffieHellman->Init(group->prime,
                                     group->prime_size,
diff --git a/test/parallel/test-crypto-dh.js b/test/parallel/test-crypto-dh.js
index 855244a70b1b93..7824800f9bee2e 100644
--- a/test/parallel/test-crypto-dh.js
+++ b/test/parallel/test-crypto-dh.js
@@ -389,7 +389,11 @@ assert.throws(
   function() {
     crypto.getDiffieHellman('unknown-group');
   },
-  /^Error: Unknown group$/,
+  {
+    name: 'Error',
+    code: 'ERR_CRYPTO_UNKNOWN_DH_GROUP',
+    message: 'Unknown group'
+  },
   'crypto.getDiffieHellman(\'unknown-group\') ' +
   'failed to throw the expected error.'
 );