diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -499,6 +499,7 @@
     'array_mergev' => 'utils/utils.php',
     'array_select_keys' => 'utils/utils.php',
     'assert_instances_of' => 'utils/utils.php',
+    'assert_same_keys' => 'utils/utils.php',
     'assert_stringlike' => 'utils/utils.php',
     'coalesce' => 'utils/utils.php',
     'csprintf' => 'xsprintf/csprintf.php',
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
@@ -231,6 +231,37 @@
       'InvalidArgumentException');
   }
 
+  public function testAssertSameKeys() {
+    $cases = array(
+      array(true, array(), array()),
+      array(true, array(0), array(1)),
+
+      array(false, array(0), array()),
+      array(false, array(), array(0)),
+
+      array(false, array('a' => 1), array('b' => 1)),
+
+      // Make sure "null" values survive "isset()" tests.
+      array(true, array('a' => 1), array('a' => null)),
+
+      // Key order should not matter.
+      array(true, array('a' => 1, 'b' => 1), array('b' => 1, 'a' => 1)),
+    );
+
+    foreach ($cases as $case) {
+      list($same_keys, $expect, $input) = $case;
+
+      $caught = null;
+      try {
+        assert_same_keys($expect, $input);
+      } catch (InvalidArgumentException $ex) {
+        $caught = $ex;
+      }
+
+      $this->assertEqual($same_keys, ($caught === null));
+    }
+  }
+
   public function testAssertStringLike() {
     $this->assertEqual(
       null,
diff --git a/src/utils/utils.php b/src/utils/utils.php
--- a/src/utils/utils.php
+++ b/src/utils/utils.php
@@ -629,6 +629,38 @@
   return $arr;
 }
 
+/**
+ * Assert that two arrays have the exact same keys, in any order.
+ *
+ * @param map Array with expected keys.
+ * @param map Array with actual keys.
+ * @return void
+ */
+function assert_same_keys(array $expect, array $actual) {
+  foreach ($expect as $key => $value) {
+    if (isset($actual[$key]) || array_key_exists($key, $actual)) {
+      continue;
+    }
+
+    throw new InvalidArgumentException(
+      pht(
+        'Expected to find key "%s", but it is not present.',
+        $key));
+
+  }
+
+  foreach ($actual as $key => $value) {
+    if (isset($expect[$key]) || array_key_exists($key, $expect)) {
+      continue;
+    }
+
+    throw new InvalidArgumentException(
+      pht(
+        'Found unexpected surplus key "%s" where no such key was expected.',
+        $key));
+  }
+}
+
 /**
  * Assert that passed data can be converted to string.
  *