diff --git a/tests/006-send/001.phpt b/tests/006-send/001.phpt
index 0dc5b0b..0603398 100644
--- a/tests/006-send/001.phpt
+++ b/tests/006-send/001.phpt
@@ -14,7 +14,8 @@ stomp_send($link, '/queue/test-06', array());
 var_dump(stomp_send($link, '/queue/test-06', ''));
 var_dump(stomp_send($link, '/queue/test-06', 'A realMessage'));
 var_dump(stomp_send($link, '/queue/test-06', 'بياريك شارون'));
-var_dump(stomp_send($link, 'بياريك شارون', 'بياريك شارون', array('receipt' => 'message-123')), stomp_error($link));
+var_dump(stomp_send($link, 'بياريك شارون', 'بياريك شارون', array('receipt' => 'message-123')));
+echo gettype(stomp_error($link));
 
 ?>
 --EXPECTF--
@@ -25,4 +26,4 @@ bool(true)
 bool(true)
 bool(true)
 bool(false)
-string(%d) "%s"
+string
diff --git a/tests/006-send/002.phpt b/tests/006-send/002.phpt
index 239e204..0c9d06c 100644
--- a/tests/006-send/002.phpt
+++ b/tests/006-send/002.phpt
@@ -14,7 +14,8 @@ $s->send('/queue/test-06', array());
 var_dump($s->send('/queue/test-06', ''));
 var_dump($s->send('/queue/test-06', 'A realMessage'));
 var_dump($s->send('/queue/test-06', 'بياريك شارون'));
-var_dump($s->send('بياريك شارون', 'بياريك شارون', array('receipt' => 'message-123')), $s->error());
+var_dump($s->send('بياريك شارون', 'بياريك شارون', array('receipt' => 'message-123')));
+echo gettype($s->error());
 
 ?>
 --EXPECTF--
@@ -25,4 +26,4 @@ bool(true)
 bool(true)
 bool(true)
 bool(false)
-string(%d) "%s"
+string
diff --git a/tests/011-commit/001.phpt b/tests/011-commit/001.phpt
index caf362b..2fccee7 100644
--- a/tests/011-commit/001.phpt
+++ b/tests/011-commit/001.phpt
@@ -17,7 +17,7 @@ var_dump($s->send('/queue/test-011-commit', 'bar', array('transaction' => 't1'))
 
 // sends a message to the queue and asks for a receipt
 $s->send('/queue/test-011-commit', 'bar', array('transaction' => 't2', 'receipt' => 'tptp'));
-var_dump($s->error());
+echo gettype($s->error()) . PHP_EOL;
 
 // commits a valid transaction
 var_dump($s->commit('t1'));
@@ -28,15 +28,15 @@ var_dump($s->commit(null));
 
 // commits a non valid transaction (a transaction id that does not exist) and asks for a receipt
 $s->commit('t2', array('receipt' => 'commit-key'));
-var_dump($s->error());
+echo gettype($s->error());
 
 unset($s);
 ?>
 --EXPECTF--
 bool(true)
 bool(true)
-string(%d) "Invalid transaction id: %s"
+string
 bool(true)
 bool(false)
 bool(true)
-string(%d) "Must specify the transaction you are committing"
+string