diff --git a/src/Client.php b/src/Client.php
index 5350b54..83970e6 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -200,11 +200,11 @@ function (Exception $e) use ($uri, $deferred) {
 
                 // Exception trace arguments are not available on some PHP 7.4 installs
                 // @codeCoverageIgnoreStart
-                foreach ($trace as &$one) {
+                foreach ($trace as $ti => $one) {
                     if (isset($one['args'])) {
-                        foreach ($one['args'] as &$arg) {
+                        foreach ($one['args'] as $ai => $arg) {
                             if ($arg instanceof \Closure) {
-                                $arg = 'Object(' . \get_class($arg) . ')';
+                                $trace[$ti]['args'][$ai] = 'Object(' . \get_class($arg) . ')';
                             }
                         }
                     }
diff --git a/tests/ClientTest.php b/tests/ClientTest.php
index 90451fb..e0e3520 100644
--- a/tests/ClientTest.php
+++ b/tests/ClientTest.php
@@ -173,11 +173,17 @@ public function testConnectorRejectsWillRejectConnection()
 
         $promise = $this->client->connect('google.com:80');
 
-        $promise->then(null, $this->expectCallableOnceWithException(
-            'RuntimeException',
-            'Connection to tcp://google.com:80 failed because connection to proxy failed (ECONNREFUSED)',
-            defined('SOCKET_ECONNREFUSED') ? SOCKET_ECONNREFUSED : 111
-        ));
+        $exception = null;
+        $promise->then(null, function ($reason) use (&$exception) {
+            $exception = $reason;
+        });
+
+        assert($exception instanceof \RuntimeException);
+        $this->assertInstanceOf('RuntimeException', $exception);
+        $this->assertEquals('Connection to tcp://google.com:80 failed because connection to proxy failed (ECONNREFUSED)', $exception->getMessage());
+        $this->assertEquals(defined('SOCKET_ECONNREFUSED') ? SOCKET_ECONNREFUSED : 111, $exception->getCode());
+        $this->assertInstanceOf('RuntimeException', $exception->getPrevious());
+        $this->assertNotEquals('', $exception->getTraceAsString());
     }
 
     public function testCancelConnectionDuringConnectionWillCancelConnection()