diff --git a/src/util/underscore.ts b/src/util/underscore.ts
index e0e2c40e5..9a32239fc 100644
--- a/src/util/underscore.ts
+++ b/src/util/underscore.ts
@@ -32,6 +32,7 @@ export function stringify (value: any): string {
   value = toValue(value)
   if (isString(value)) return value
   if (isNil(value)) return ''
+  if (isArray(value)) return value.map(x => stringify(x)).join('')
   return String(value)
 }
 
diff --git a/test/e2e/issues.ts b/test/e2e/issues.ts
index 93ad7b4e0..4236e43a4 100644
--- a/test/e2e/issues.ts
+++ b/test/e2e/issues.ts
@@ -103,7 +103,7 @@ describe('Issues', function () {
     const html = await engine.parseAndRender(
       `{{ 'a \n b \n c' | newline_to_br | split: '<br />' }}`
     )
-    expect(html).to.equal('a ,\n b ,\n c')
+    expect(html).to.equal('a \n b \n c')
   })
   it('#342 New lines in logical operator', async () => {
     const engine = new Liquid()
diff --git a/test/e2e/parse-and-render.ts b/test/e2e/parse-and-render.ts
index 6a0ba9114..c86bd79a2 100644
--- a/test/e2e/parse-and-render.ts
+++ b/test/e2e/parse-and-render.ts
@@ -15,7 +15,7 @@ describe('.parseAndRender()', function () {
   it('should stringify array ', async function () {
     var ctx = { arr: [-2, 'a'] }
     const html = await engine.parseAndRender('{{arr}}', ctx)
-    return expect(html).to.equal('-2,a')
+    return expect(html).to.equal('-2a')
   })
   it('should render undefined as empty', async function () {
     const html = await engine.parseAndRender('foo{{zzz}}bar', {})
@@ -41,9 +41,9 @@ describe('.parseAndRender()', function () {
     const ctx = { obj: [1, 2] }
     const template = engine.parse('{{obj}}')
     const result = await engine.render(template, ctx)
-    expect(result).to.equal('1,2')
+    expect(result).to.equal('12')
     const result2 = await engine.render(template, ctx)
-    expect(result2).to.equal('1,2')
+    expect(result2).to.equal('12')
   })
   it('should support the "join" filter', async function () {
     var ctx = { names: ['alice', 'bob'] }
diff --git a/test/integration/builtin/filters/array.ts b/test/integration/builtin/filters/array.ts
index 3561eb329..f28941dcd 100644
--- a/test/integration/builtin/filters/array.ts
+++ b/test/integration/builtin/filters/array.ts
@@ -36,7 +36,7 @@ describe('filters/array', function () {
   describe('map', () => {
     it('should support map', function () {
       const posts = [{ category: 'foo' }, { category: 'bar' }]
-      return test('{{posts | map: "category"}}', { posts }, 'foo,bar')
+      return test('{{posts | map: "category"}}', { posts }, 'foobar')
     })
     it('should normalize non-array input', function () {
       const post = { category: 'foo' }
@@ -53,7 +53,7 @@ describe('filters/array', function () {
   describe('compact', () => {
     it('should compact array', function () {
       const posts = [{ category: 'foo' }, { category: 'bar' }, { foo: 'bar' }]
-      return test('{{posts | map: "category" | compact}}', { posts }, 'foo,bar')
+      return test('{{posts | map: "category" | compact}}', { posts }, 'foobar')
     })
   })
   describe('reverse', function () {
diff --git a/test/integration/builtin/tags/assign.ts b/test/integration/builtin/tags/assign.ts
index dcf34e919..f27c60a2b 100644
--- a/test/integration/builtin/tags/assign.ts
+++ b/test/integration/builtin/tags/assign.ts
@@ -24,7 +24,7 @@ describe('tags/assign', function () {
   it('should assign as array', async function () {
     const src = '{% assign foo=(1..3) %}{{foo}}'
     const html = await liquid.parseAndRender(src)
-    return expect(html).to.equal('1,2,3')
+    return expect(html).to.equal('123')
   })
   it('should assign as filter result', async function () {
     const src = '{% assign foo="a b" | capitalize | split: " " | first %}{{foo}}'