diff --git a/src/array/replaceOrAppend.ts b/src/array/replaceOrAppend.ts
index 9aac4b04..0ad0add5 100644
--- a/src/array/replaceOrAppend.ts
+++ b/src/array/replaceOrAppend.ts
@@ -19,10 +19,10 @@ export function replaceOrAppend<T>(
   newItem: T,
   match: (a: T, idx: number) => boolean,
 ): T[] {
-  if (!array && !newItem) {
+  if (!array && newItem == null) {
     return []
   }
-  if (!newItem) {
+  if (newItem == null) {
     return [...array]
   }
   if (!array) {
diff --git a/tests/array/replaceOrAppend.test.ts b/tests/array/replaceOrAppend.test.ts
index a71f13d6..863631a6 100644
--- a/tests/array/replaceOrAppend.test.ts
+++ b/tests/array/replaceOrAppend.test.ts
@@ -44,4 +44,11 @@ describe('replaceOrAppend', () => {
     const result = _.replaceOrAppend(letters, 'XX', x => x === 'x')
     expect(result).toEqual(lettersXX)
   })
+  test('replaces a falsy new item instead of treating it as missing', () => {
+    expect(_.replaceOrAppend([1, 2, 3], 0, n => n === 2)).toEqual([1, 0, 3])
+    expect(_.replaceOrAppend([true], false, x => x === true)).toEqual([false])
+  })
+  test('appends a falsy new item when nothing matches', () => {
+    expect(_.replaceOrAppend([1, 2, 3], 0, n => n > 100)).toEqual([1, 2, 3, 0])
+  })
 })