diff --git a/src/Symfony/Component/Process/Tests/SimpleProcessTest.php b/src/Symfony/Component/Process/Tests/SimpleProcessTest.php
index ccaa78df2459..ca4522acf10e 100644
--- a/src/Symfony/Component/Process/Tests/SimpleProcessTest.php
+++ b/src/Symfony/Component/Process/Tests/SimpleProcessTest.php
@@ -167,7 +167,7 @@ public function testKillSignalTerminatesProcessCleanly()
             $process = $this->getProcess('php -r "echo \'foo\'; sleep(1); echo \'bar\';"');
             $process->run(function () use ($process) {
                 if ($process->isRunning()) {
-                    $process->signal(SIGKILL);
+                    $process->signal(defined('SIGKILL') ? SIGKILL : 9);
                 }
             });
         } catch (RuntimeException $e) {
@@ -183,7 +183,7 @@ public function testTermSignalTerminatesProcessCleanly()
             $process = $this->getProcess('php -r "echo \'foo\'; sleep(1); echo \'bar\';"');
             $process->run(function () use ($process) {
                 if ($process->isRunning()) {
-                    $process->signal(SIGTERM);
+                    $process->signal(defined('SIGTERM') ? SIGTERM : 15);
                 }
             });
         } catch (RuntimeException $e) {