diff --git a/types/pem-jwk/index.d.ts b/types/pem-jwk/index.d.ts
index 3a9d32c112..c206b12db2 100644
--- a/types/pem-jwk/index.d.ts
+++ b/types/pem-jwk/index.d.ts
@@ -3,25 +3,17 @@
 // Definitions by: Alessio Paccoia <https://github.com/alessiopcc>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
-export function pem2jwk(pem: string): RSAJWK;
-export function jwk2pem(jwk: RSAJWK): string;
-
-export type RSAJWK = RSAPrivateJWK | RSAPublicJWK;
-
-export interface RSAPrivateJWK {
+export interface RSA_JWK {
     kty: string;
     n: string;
     e: string;
-    d: string;
-    p: string;
-    q: string;
-    dp: string;
-    dq: string;
-    qi: string;
+    d?: string;
+    p?: string;
+    q?: string;
+    dp?: string;
+    dq?: string;
+    qi?: string;
 }
 
-export interface RSAPublicJWK {
-    kty: string;
-    n: string;
-    e: string;
-}
+export function pem2jwk(rsa_pem: string): RSA_JWK;
+export function jwk2pem(rsa_jwk: RSA_JWK): string;
diff --git a/types/pem-jwk/pem-jwk-tests.ts b/types/pem-jwk/pem-jwk-tests.ts
index 4d0c774d9f..8876f14373 100644
--- a/types/pem-jwk/pem-jwk-tests.ts
+++ b/types/pem-jwk/pem-jwk-tests.ts
@@ -1,4 +1,17 @@
-import * as pem_jwk from "pem-jwk";
+import { jwk2pem, pem2jwk, RSA_JWK } from "pem-jwk";
 
-pem_jwk.jwk2pem({kty: 'RSA', n: 'base64 modulus', e: 'base64 exponent'}); // $ExpectType string
-pem_jwk.pem2jwk('PEM RSA String'); // $ExpectType pem_jwk.RSAJWK
+const rsa_pem = `-----BEGIN PUBLIC KEY-----
+MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDh6RzHEsTFjD8NlB4echurwfV2
+Zrlcg0k2JoP0Z3QAgXPMwJynvs2LeBHYaOFzGzjXRKsvaLwc5PjP3NcqcP3KkX5y
+1VA31VrJLfFbXthi0a8c/UBwxJD8i4S35OKr6yui3bJatgYWrSQ4MT9ktaS1TP9l
+XBW58V4VlkypTaQTSQIDAQAB
+-----END PUBLIC KEY-----`;
+
+const rsa_jwk: RSA_JWK = {
+    kty: 'RSA',
+    n: '4ekcxxLExYw_DZQeHnIbq8H1dma5XINJNiaD9Gd0AIFzzMCcp77Ni3gR2Gjhcxs410SrL2i8HOT4z9zXKnD9ypF-ctVQN9VayS3xW17YYtGvHP1AcMSQ_IuEt-Tiq-srot2yWrYGFq0kODE_ZLWktUz_ZVwVufFeFZZMqU2kE0k',
+    e: 'AQAB'
+};
+
+jwk2pem(rsa_jwk); // $ExpectType string
+pem2jwk(rsa_pem); // $ExpectType RSA_JWK
diff --git a/types/pem-jwk/tsconfig.json b/types/pem-jwk/tsconfig.json
index b2562d8bae..992cd51066 100644
--- a/types/pem-jwk/tsconfig.json
+++ b/types/pem-jwk/tsconfig.json
@@ -6,6 +6,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
+        "strictFunctionTypes": true,
         "strictNullChecks": true,
         "baseUrl": "../",
         "typeRoots": [