diff --git a/src/util.mjs b/src/util.mjs
index 7db35511..a7b7d4f3 100644
--- a/src/util.mjs
+++ b/src/util.mjs
@@ -20,7 +20,7 @@ export function merge(a, b) {
 
   if (Array.isArray(a)) {
     if (Array.isArray(b)) {
-      return [...a, ...a.filter(x => !b.includes(x))];
+      return [...a, ...a.filter(x => !b.find(e => equal(e, x)))];
     }
     return [...a, b];
   }
@@ -44,3 +44,26 @@ export function merge(a, b) {
 
   return a;
 }
+
+export function equal(x, y) {
+  const xType = typeof x;
+  const yType = typeof y;
+
+  if (xType === "object" && yType === "object" && (x !== null && y !== null)) {
+    const xKeys = Object.keys(x);
+    const yKeys = Object.keys(y);
+    const xValues = Object.values(x);
+    const yValues = Object.values(y);
+
+    if (xKeys.length !== yKeys.length) return false;
+
+    for (let i = 0; i < xKeys.length; i++)
+      if (xKeys[i] !== yKeys[i]) return false;
+
+    for (let i = 0; i < xValues.length; i++)
+      if (!equal(xValues[i], yValues[i])) return false;
+  } else {
+    if (x !== y) return false;
+  }
+  return true;
+}
diff --git a/tests/merge-test.mjs b/tests/merge-test.mjs
index 66e7f66b..45377206 100644
--- a/tests/merge-test.mjs
+++ b/tests/merge-test.mjs
@@ -1,10 +1,11 @@
 import test from "ava";
 import { expand } from "../src/expander.mjs";
+import { equal } from "../src/util.mjs";
 
 test("merge", async t =>
   t.deepEqual(
     await expand(
-      { a: { b: "${1 - 1}", b1: 2,  b3: 3}, a1: ["a"], a2: { b1: 7 } },
+      { a: { b: "${1 - 1}", b1: 2, b3: 3 }, a1: ["a"], a2: { b1: 7 } },
       { default: { a: { b1: 1, b2: "${1 + 2}", b3: null } } }
     ),
     {
@@ -14,6 +15,14 @@ test("merge", async t =>
     }
   ));
 
+test("merge complex array", async t =>
+  t.deepEqual(
+    await expand([{ a: 1 }, { b: 2 }], {
+      default: [{ a: 1 }, { b: 2 }]
+    }),
+    [{ a: 1 }, { b: 2 }]
+  ));
+
 test("merge array", async t =>
   t.deepEqual(
     await expand(
@@ -40,3 +49,11 @@ test("merge array", async t =>
       }
     }
   ));
+
+
+test("eq1",t =>{
+  t.true(equal(1,1));
+  t.true(equal([1],[1]));
+  t.true(equal([{a:1}],[{a:1}]));
+  t.false(equal([{a:1}],[{b:1}]));
+});