diff --git a/README.md b/README.md
index aa88fd2..a30f374 100644
--- a/README.md
+++ b/README.md
@@ -168,6 +168,10 @@ Tests if the value is a valid hash.
 ### Integer
 Tests if the value is an integer.
 
+#### Arguments
+- `allowString` (optional) - whether the assert accepts string inputs or not.
+- `unsigned` (optional) - whether the assert should consider only unsigned values or not.
+
 ### InternationalBankAccountNumber (*IBAN*)
 Tests if the value is a valid International Bank Account Number (_IBAN_) as defined in the [13616-1](http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=41031) standard.
 
diff --git a/src/asserts/integer-assert.js b/src/asserts/integer-assert.js
index ae6c095..52e535b 100644
--- a/src/asserts/integer-assert.js
+++ b/src/asserts/integer-assert.js
@@ -9,13 +9,16 @@ import { Validator, Violation } from 'validator.js';
  * Int regex.
  */
 
-const int = /^(?:[-+]?(?:0|[1-9][0-9]*))$/;
+const int = {
+  signed: /^(?:[-+]?(?:0|[1-9][0-9]*))$/,
+  unsigned: /^(?:\d+)$/
+};
 
 /**
  * Export `IntegerAssert`.
  */
 
-export default function integerAssert() {
+export default function integerAssert({ allowString = false, unsigned = false } = {}) {
   /**
    * Class name.
    */
@@ -27,11 +30,15 @@ export default function integerAssert() {
    */
 
   this.validate = value => {
-    if (typeof value !== 'number') {
+    if (typeof value !== 'number' && !allowString) {
       throw new Violation(this, value, { value: Validator.errorCode.must_be_a_number });
     }
 
-    if (int.test(value) !== true) {
+    if (unsigned && int.unsigned.test(value) !== true) {
+      throw new Violation(this, value);
+    }
+
+    if (int.signed.test(value) !== true) {
       throw new Violation(this, value);
     }
 
diff --git a/test/asserts/integer-assert_test.js b/test/asserts/integer-assert_test.js
index a0fdb4e..b141560 100644
--- a/test/asserts/integer-assert_test.js
+++ b/test/asserts/integer-assert_test.js
@@ -44,7 +44,31 @@ describe('IntegerAssert', () => {
     }
   });
 
+  it('should throw an error if strings are allowed but input is not valid', () => {
+    try {
+      new Assert().Integer({ allowString: true }).validate(' 1');
+
+      should.fail();
+    } catch (e) {
+      e.show().assert.should.equal('Integer');
+    }
+  });
+
+  it('should throw an error if only unsigned integers are allowed but input is not valid', () => {
+    try {
+      new Assert().Integer({ unsigned: true }).validate(-1);
+
+      should.fail();
+    } catch (e) {
+      e.show().assert.should.equal('Integer');
+    }
+  });
+
+  it('should accept an unsigned integer as a string if strings are allowed', () => {
+    new Assert().Integer({ allowString: true, unsigned: true }).validate('1');
+  });
+
   it('should accept an integer', () => {
-    new Assert().Integer().validate(1);
+    new Assert().Integer().validate(+1);
   });
 });