diff --git a/README.md b/README.md
index f00443a..a95807d 100644
--- a/README.md
+++ b/README.md
@@ -881,6 +881,17 @@ $point2d->y = 20;
 $point3d = O::assoc("z", 30, $point2d); // {"x": 10, "y": 20, "z": 30}
 ```
 
+```php
+$point2d = [
+  "x" => 10,
+  "y" => 20
+];
+
+$point3d = O::assoc("z", 30, $point2d); // ["x" => 10, "y" => 20, "z" => 30]
+```
+
+**Does not work on arrays with numeric keys!**
+
 </details>
 
 <details>
@@ -897,6 +908,18 @@ $point3d->z = 30;
 $point2d = O::dissoc("z", 30, $point3d); // {"x": 10, "y": 20}
 ```
 
+```php
+$point3d = [
+  "x" => 10,
+  "y" => 20,
+  "z" => 30
+];
+
+$point2d = O::dissoc("z", 30, $point3d); // ["x" => 10, "y" => 30]
+```
+
+**Does not work on arrays with numeric keys!**
+
 </details>
 
 <details>
diff --git a/src/O.php b/src/O.php
index 8315510..611aedc 100644
--- a/src/O.php
+++ b/src/O.php
@@ -45,14 +45,22 @@ function ($result, $key) use ($data) {
     }
 
     // O::assoc('foo', 'bar', {}) -> {foo: 'bar'}
-    public static function assoc(string $key, $value, object $data): object {
-        $data->{$key} = $value;
+    public static function assoc(string $key, $value, $data): object {
+        if (O::isObject($data)) {
+            $data->{$key} = $value;
+        } elseif(A::isArray($data) && A::isAssoc($data)) {
+            $data[$key] = $value;
+        }
         return $data;
     }
 
     // O::dissoc('foo', {foo: 'bar', fizz: 'buzz'}) -> {fizz: 'buzz'}
-    public static function dissoc(string $key, object $data): object {
-        unset($data->{$key});
+    public static function dissoc(string $key, $data): object {
+        if (O::isObject($data)) {
+            unset($data->{$key});
+        } elseif(A::isArray($data) && A::isAssoc($data)) {
+            unset($data[$key]);
+        }
         return $data;
     }