diff --git a/index.js b/index.js
index f8d6af2..0d8d622 100644
--- a/index.js
+++ b/index.js
@@ -103,4 +103,8 @@ deepmerge.all = function deepmergeAll(array, options) {
 	}, {})
 }
 
+deepmerge.customMergeIgnoreEmptyValues = (key, target, source) => !target || target === ''
+	? () => source
+	: () => target;
+
 module.exports = deepmerge
diff --git a/test/merge.js b/test/merge.js
index 662408e..955d21d 100644
--- a/test/merge.js
+++ b/test/merge.js
@@ -673,7 +673,7 @@ test('customMerge without overwriting with null or empty string', function(t) {
 	var target = { very: { nested: { thing: 'derp' } } };
 
 	var res = merge(target, src, {
-		customMerge: (key, target, source) => !target || target === '' ? () => source : () => target,
+		customMerge: merge.customMergeIgnoreEmptyValues,
 	});
 
 	t.deepEqual(res, { someNewVariable: 'herp',very: {nested: { thing: 'derp'}} })