diff --git a/src/utils/__tests__/PhutilUtilsTestCase.php b/src/utils/__tests__/PhutilUtilsTestCase.php
--- a/src/utils/__tests__/PhutilUtilsTestCase.php
+++ b/src/utils/__tests__/PhutilUtilsTestCase.php
@@ -389,6 +389,62 @@
     $this->assertEqual(array('x' => 'x'), array_fuse(array('x')));
   }
 
+  public function testArrayMergeRecursiveOverrule() {
+    $cases = array(
+      array(
+        'original' => array('foo'),
+        'overrule' => array(),
+        'result' => array('foo')
+      ),
+      array(
+        'original' => array(),
+        'overrule' => array('foo'),
+        'result' => array('foo')
+      ),
+      array(
+        'original' => array('bar'),
+        'overrule' => array('foo'),
+        'result' => array('foo')
+      ),
+      array(
+        'original' => array('bar' => 1),
+        'overrule' => array('foo' => 2),
+        'result' => array('bar' => 1, 'foo' => 2)
+      ),
+      array(
+        'original' => array('bar' => 1),
+        'overrule' => array('bar' => 2),
+        'result' => array('bar' => 2)
+      ),
+      array(
+        'original' => array('bar' => 1, 'bar-1' => 'stringValue'),
+        'overrule' => array('foo' => 2),
+        'result' => array('bar' => 1, 'bar-1' => 'stringValue', 'foo' => 2)
+      ),
+      array(
+        'original' => array('bar' => array('foo')),
+        'overrule' => array('bar' => 2),
+        'result' => array('bar' => 2)
+      ),
+      array(
+        'original' => array('bar' => array('foo')),
+        'overrule' => array('bar' => array('bar')),
+        'result' => array('bar' => array('bar'))
+      ),
+      array(
+        'original' => array('bar' => array('bar' => 1, 'foo' => 1)),
+        'overrule' => array('bar' => array('bar' => 2)),
+        'result' => array('bar' => array('bar' => 2, 'foo' => 1))
+      )
+    );
+
+    foreach ($cases as $case) {
+      $this->assertEqual(
+        array_merge_recursive_overrule(
+          $case['original'], $case['overrule']), $case['result']);
+    }
+  }
+
   public function testArrayInterleave() {
     $this->assertEqual(array(), array_interleave('x', array()));
     $this->assertEqual(array('y'), array_interleave('x', array('y')));
diff --git a/src/utils/utils.php b/src/utils/utils.php
--- a/src/utils/utils.php
+++ b/src/utils/utils.php
@@ -735,6 +735,36 @@
   return call_user_func_array('array_merge', $arrayv);
 }
 
+/**
+ * Merges two arrays recursively and "binary safe" (integer keys are overridden
+ * as well), overruling similar values in the original array with the values of
+ * the overrule array. In case of identical keys, ie. keeping the values of the
+ * overrule array.
+ *
+ * The differences to the existing PHP function array_merge_recursive() is that
+ * elements or the original array get overwritten if the same key is present in
+ * the overrule array.
+ *
+ * @param array  Array with the original values
+ * @param array  Array with the values that should overrule the values
+ *               from the original array
+ * @return array the overruled array
+ */
+function array_merge_recursive_overrule(array $original, array $overrule) {
+  foreach (array_keys($overrule) as $key) {
+    if (isset(
+      $original[$key]) &&
+      is_array($original[$key]) &&
+      is_array($overrule[$key])) {
+      $original[$key] = array_merge_recursive_overrule(
+        $original[$key], $overrule[$key]);
+    } else {
+      $original[$key] = $overrule[$key];
+    }
+  }
+
+  return $original;
+}
 
 /**
  * Split a corpus of text into lines. This function splits on "\n", "\r\n", or