diff --git a/types/node-rsa/index.d.ts b/types/node-rsa/index.d.ts
index 63d569378d..f7e92c071b 100644
--- a/types/node-rsa/index.d.ts
+++ b/types/node-rsa/index.d.ts
@@ -31,7 +31,10 @@ declare class NodeRSA {
     /**
      * Export key to PEM string, PEM/DER Buffer or components.
      */
-    exportKey(format?: NodeRSA.Format): NodeRSA.Key;
+    exportKey(format?: NodeRSA.FormatPem): string;
+    exportKey(format: NodeRSA.FormatDer): Buffer;
+    exportKey(format: NodeRSA.FormatComponentsPrivate): NodeRSA.KeyComponentsPrivate;
+    exportKey(format: NodeRSA.FormatComponentsPublic): NodeRSA.KeyComponentsPublic;
 
     isPrivate(): boolean;
 
@@ -85,20 +88,26 @@ declare class NodeRSA {
 }
 
 declare namespace NodeRSA {
-    type Key = string | Buffer | KeyComponents;
+    type Key = string | Buffer | KeyComponentsPrivate | KeyComponentsPublic;
     type Data = string | object | any[];
 
-    type Format =
+    type FormatPem =
         | 'private' | 'public'
-        | 'pkcs1' | 'pkcs1-pem' | 'pkcs1-der'
-        | 'pkcs1-private' | 'pkcs1-private-pem' | 'pkcs1-private-der'
-        | 'pkcs1-public' | 'pkcs1-public-pem' | 'pkcs1-public-der'
-        | 'pkcs8' | 'pkcs8-pem' | 'pkcs8-der'
-        | 'pkcs8-private' | 'pkcs8-private-pem' | 'pkcs8-private-der'
-        | 'pkcs8-public' | 'pkcs8-public-pem' | 'pkcs8-public-der'
+        | 'pkcs1' | 'pkcs1-pem'
+        | 'pkcs1-private' | 'pkcs1-private-pem'
+        | 'pkcs1-public' | 'pkcs1-public-pem'
+        | 'pkcs8' | 'pkcs8-pem'
+        | 'pkcs8-private' | 'pkcs8-private-pem'
+        | 'pkcs8-public' | 'pkcs8-public-pem';
+    type FormatDer =
+        | 'pkcs1-der' | 'pkcs1-private-der' | 'pkcs1-public-der'
+        | 'pkcs8-der' | 'pkcs8-private-der' | 'pkcs8-public-der';
+    type FormatComponentsPrivate =
         | 'components' | 'components-pem' | 'components-der'
-        | 'components-private' | 'components-private-pem' | 'components-private-der'
+        | 'components-private' | 'components-private-pem' | 'components-private-der';
+    type FormatComponentsPublic =
         | 'components-public' | 'components-public-pem' | 'components-public-der';
+    type Format = FormatPem | FormatDer | FormatComponentsPrivate | FormatComponentsPublic;
 
     type EncryptionScheme = 'pkcs1_oaep' | 'pkcs1';
 
@@ -124,7 +133,7 @@ declare namespace NodeRSA {
         | 'ascii' | 'utf8' | 'utf16le' | 'ucs2' | 'latin1'
         | 'base64' | 'hex' | 'binary' | 'buffer';
 
-    interface KeyComponents {
+    interface KeyComponentsPrivate {
         n: Buffer;
         e: Buffer | number;
         d: Buffer;
@@ -135,6 +144,11 @@ declare namespace NodeRSA {
         coeff: Buffer;
     }
 
+    interface KeyComponentsPublic {
+        n: Buffer;
+        e: Buffer | number;
+    }
+
     interface KeyBits {
         /**
          * The length of the key in bits.
diff --git a/types/node-rsa/node-rsa-tests.ts b/types/node-rsa/node-rsa-tests.ts
index 0f8defacbd..eac9a0397b 100644
--- a/types/node-rsa/node-rsa-tests.ts
+++ b/types/node-rsa/node-rsa-tests.ts
@@ -26,8 +26,10 @@ Es+KCn25OKXR/FJ5fu6A6A+MptABL3r8SEjlpLc=
 
 const keyData = '-----BEGIN PUBLIC KEY----- ... -----END PUBLIC KEY-----';
 key.importKey(keyData, 'pkcs8');
-const publicDer = key.exportKey('pkcs8-public-der');
-const privateDer = key.exportKey('pkcs1-der');
+const defaultPem: string = key.exportKey();
+const publicPem: string = key.exportKey('pkcs8-public-pem');
+const publicDer: Buffer = key.exportKey('pkcs8-public-der');
+const privateDer: Buffer = key.exportKey('pkcs1-der');
 key.importKey({
 	n: new Buffer('0086fa9ba066685845fc03833a9699c8baefb53cfbf19052a7f10f1eaa30488cec1ceb752bdff2df9fad6c64b3498956e7dbab4035b4823c99a44cc57088a23783', 'hex'),
 	e: 65537,
@@ -39,6 +41,17 @@ key.importKey({
 	coeff: new Buffer('00b399675e5e81506b729a777cc03026f0b2119853dfc5eb124610c0ab82999e45', 'hex')
 }, 'components');
 const publicComponents = key.exportKey('components-public');
+let b: Buffer = publicComponents.n;
+let bn: Buffer|number = publicComponents.e;
+const privateComponents = key.exportKey('components-private');
+b = privateComponents.n;
+bn = privateComponents.e;
+b = privateComponents.d;
+b = privateComponents.p;
+b = privateComponents.q;
+b = privateComponents.dmp1;
+b = privateComponents.dmq1;
+b = privateComponents.coeff;
 
 key.isPrivate();
 key.isPublic(true);