diff --git a/run-tests.php b/run-tests.php
index 81f218b..9516490 100755
--- a/run-tests.php
+++ b/run-tests.php
@@ -451,6 +451,12 @@ if ($compression) {
 	$output_file = 'compress.zlib://' . $output_file . '.gz';
 }
 
+$max_jobs = false;
+
+if (extension_loaded('pcntl') && extension_loaded('sysvmsg')) {
+    $max_jobs = 1;
+}
+
 $just_save_results = false;
 $leak_check = false;
 $html_output = false;
@@ -551,6 +557,14 @@ if (isset($argc) && $argc > 1) {
 					$ini_overwrites[] = $argv[++$i];
 					break;
 				//case 'h'
+				case 'j':
+					if ($max_jobs !== false) {
+						$max_jobs = (int)$argv[++$i];
+						if ($max_jobs < 1) {
+							$max_jobs = 1;
+						}
+					}
+					break;
 				case '--keep-all':
 					foreach($cfgfiles as $file) {
 						$cfg['keep'][$file] = true;
@@ -665,6 +679,9 @@ Options:
     -d foo=bar  Pass -d option to the php binary (Define INI entry foo
                 with value 'bar').
 
+    -j <n>      Maximum number of jobs to run in parallel (defaults to 1,
+                requires pcntl and sysvmsg).
+
     -m          Test for memory leaks with Valgrind.
 
     -p <php>    Specify PHP executable to run.
@@ -1082,9 +1099,30 @@ function system_with_timeout($commandline, $env = null, $stdin = null)
 	return $data;
 }
 
+function reap_jobs($queue, &$results)
+{
+	// process messages aggresively to avoid
+	// saturating the queue, stalling childs
+	// waiting for space in the queue to exit
+	while (msg_receive($queue, 0, $null, 4096, $msg, true, MSG_IPC_NOWAIT))
+		$results[$msg['index']] = $msg['result'];
+	return pcntl_wait($null);
+}
+
 function run_all_tests($test_files, $env, $redir_tested = null)
 {
 	global $test_results, $failed_tests_file, $php, $test_cnt, $test_idx;
+	global $max_jobs;
+
+	$run_once = 0;
+
+	if ($max_jobs !== false) {
+		$jobs_avail = $max_jobs;
+		do {
+			$queue_key = mt_rand();
+		} while (function_exists('msg_queue_exists') && msg_queue_exists($queue_key));
+		$queue = msg_get_queue($queue_key);
+	}
 
 	foreach($test_files as $name) {
 
@@ -1100,15 +1138,56 @@ function run_all_tests($test_files, $env, $redir_tested = null)
 			$index = $name;
 		}
 		$test_idx++;
+
+		if ($max_jobs && ($max_jobs > 1 || $jobs_avail == 0)) {
+			if (!$jobs_avail) {
+				if (reap_jobs($queue, $test_results) > 0)
+				    $jobs_avail++;
+			}
+			$pid = pcntl_fork();
+			if ($pid == -1) {
+			    // Do nothing special, test will be run by
+			    // the parent process.
+			    // Decrement $jobs_avail and $max_jobs so that if
+			    // future calls to fork fail we will end up
+			    // disabling multi-jobs support without
+			    // leaving childs behind.
+			    $jobs_avail--;
+			    $max_jobs--;
+			} else if ($pid) {
+			    // parent process
+			    $jobs_avail--;
+			    continue;
+			} else {
+			    // child process:
+			    $max_jobs = false;
+			    $run_once = 1;
+			}
+		}
+
 		$result = run_test($php, $name, $env);
 
 		if (!is_array($name) && $result != 'REDIR') {
-			$test_results[$index] = $result;
+			// send the results back to the parent process
+			// if there's an active queue
+			if (isset($queue))
+				msg_send($queue, 1, array('index' => $index, 'result' => $result));
+			else
+				$test_results[$index] = $result;
 			if ($failed_tests_file && ($result == 'XFAILED' || $result == 'FAILED' || $result == 'WARNED' || $result == 'LEAKED')) {
 				fwrite($failed_tests_file, "$index\n");
 			}
 		}
+		if ($run_once) exit;
 	}
+
+	if ($max_jobs !== false) {
+		// check for messages one last time before removing the queue
+		// reap jobs at the same time
+		while (reap_jobs($queue, $test_results) > 0);
+		msg_remove_queue($queue);
+	}
+
 }
 
 //