diff --git a/node/node.d.ts b/node/node.d.ts
index bd0429ad12..45dc16a0f4 100644
--- a/node/node.d.ts
+++ b/node/node.d.ts
@@ -1045,14 +1045,19 @@ declare module "crypto" {
     export interface Credentials { context?: any; }
     export function createCredentials(details: CredentialDetails): Credentials;
     export function createHash(algorithm: string): Hash;
-    export function createHmac(algorithm: string, key: any): Hmac;
+    export function createHmac(algorithm: string, key: string): Hmac;
+    export function createHmac(algorithm: string, key: Buffer): Hmac;
     interface Hash {
         update(data: any, input_encoding?: string): Hash;
-        digest(encoding?: string): any;
+        digest(encoding: 'buffer'): Buffer;
+        digest(encoding: string): any;
+        digest(): Buffer;
     }
     interface Hmac {
         update(data: any, input_encoding?: string): Hmac;
-        digest(encoding?: string): any;
+        digest(encoding: 'buffer'): Buffer;
+        digest(encoding: string): any;
+        digest(): any;
     }
     export function createCipher(algorithm: string, password: any): Cipher;
     export function createCipheriv(algorithm: string, key: any, iv: any): Cipher;
@@ -1060,9 +1065,9 @@ declare module "crypto" {
         update(data: any, input_encoding?: string, output_encoding?: string): string;
         final(output_encoding?: string): string;
         setAutoPadding(auto_padding: boolean): void;
-        createDecipher(algorithm: string, password: any): Decipher;
-        createDecipheriv(algorithm: string, key: any, iv: any): Decipher;
     }
+    export function createDecipher(algorithm: string, password: any): Decipher;
+    export function createDecipheriv(algorithm: string, key: any, iv: any): Decipher;
     interface Decipher {
         update(data: any, input_encoding?: string, output_encoding?: string): void;
         final(output_encoding?: string): string;