diff --git a/test/isNull/isNull.test.js b/test/isNull/isNull.test.js
index 74ae0ff89..4244872b0 100644
--- a/test/isNull/isNull.test.js
+++ b/test/isNull/isNull.test.js
@@ -5,6 +5,8 @@ test('Testing isNull', (t) => {
 	//For more information on all the methods supported by tape
 	//Please go to https://github.com/substack/tape
 	t.true(typeof isNull === 'function', 'isNull is a Function');
+	t.equal(isNull(null), true, "passed argument is a null");
+	t.equal(isNull(NaN), false, "passed argument is a null");
 	//t.deepEqual(isNull(args..), 'Expected');
 	//t.equal(isNull(args..), 'Expected');
 	//t.false(isNull(args..), 'Expected');
diff --git a/test/isNumber/isNumber.test.js b/test/isNumber/isNumber.test.js
index 5a88f88bd..3845c0818 100644
--- a/test/isNumber/isNumber.test.js
+++ b/test/isNumber/isNumber.test.js
@@ -5,6 +5,9 @@ test('Testing isNumber', (t) => {
 	//For more information on all the methods supported by tape
 	//Please go to https://github.com/substack/tape
 	t.true(typeof isNumber === 'function', 'isNumber is a Function');
+	t.equal(isNumber(1), true, "passed argument is a number");
+	t.equal(isNumber('1'), false, "passed argument is not a number");
+
 	//t.deepEqual(isNumber(args..), 'Expected');
 	//t.equal(isNumber(args..), 'Expected');
 	//t.false(isNumber(args..), 'Expected');