diff --git a/UPGRADE-3.4.md b/UPGRADE-3.4.md
index 763e45285e..a8dc19791f 100644
--- a/UPGRADE-3.4.md
+++ b/UPGRADE-3.4.md
@@ -300,6 +300,8 @@ Process
  * The `Symfony\Component\Process\ProcessBuilder` class has been deprecated,
    use the `Symfony\Component\Process\Process` class directly instead.
 
+ * Calling `Process::start()` without setting a valid working directory (via `setWorkingDirectory()` or constructor) beforehand is deprecated and will throw an exception in 4.0.
+
 Profiler
 --------
 
diff --git a/UPGRADE-4.0.md b/UPGRADE-4.0.md
index 11e7cdfe92..20df7ec98f 100644
--- a/UPGRADE-4.0.md
+++ b/UPGRADE-4.0.md
@@ -639,6 +639,8 @@ Ldap
 Process
 -------
 
+ * Passing a not existing working directory to the constructor of the `Symfony\Component\Process\Process` class is not supported anymore.
+
  * The `Symfony\Component\Process\ProcessBuilder` class has been removed,
    use the `Symfony\Component\Process\Process` class directly instead.
 
diff --git a/src/Symfony/Component/Process/CHANGELOG.md b/src/Symfony/Component/Process/CHANGELOG.md
index 7193c498d4..c5cdb99441 100644
--- a/src/Symfony/Component/Process/CHANGELOG.md
+++ b/src/Symfony/Component/Process/CHANGELOG.md
@@ -5,6 +5,7 @@ CHANGELOG
 -----
 
  * deprecated the ProcessBuilder class
+ * deprecated calling `Process::start()` without setting a valid working directory beforehand (via `setWorkingDirectory()` or constructor)
 
 3.3.0
 -----
diff --git a/src/Symfony/Component/Process/Process.php b/src/Symfony/Component/Process/Process.php
index f1f7d30f8a..2a73814d77 100644
--- a/src/Symfony/Component/Process/Process.php
+++ b/src/Symfony/Component/Process/Process.php
@@ -332,6 +332,14 @@ class Process implements \IteratorAggregate
             $ptsWorkaround = fopen(__FILE__, 'r');
         }
 
+        if (!is_dir($this->cwd)) {
+            if ('\\' === DIRECTORY_SEPARATOR) {
+                throw new RuntimeException('The provided cwd does not exist.');
+            }
+
+            @trigger_error('The provided cwd does not exist. Command is currently ran against getcwd(). This behavior is deprecated since version 3.4 and will be removed in 4.0.', E_USER_DEPRECATED);
+        }
+
         $this->process = proc_open($commandline, $descriptors, $this->processPipes->pipes, $this->cwd, $env, $this->options);
 
         foreach ($envBackup as $k => $v) {
diff --git a/src/Symfony/Component/Process/Tests/ProcessTest.php b/src/Symfony/Component/Process/Tests/ProcessTest.php
index d939604750..1ad601c715 100644
--- a/src/Symfony/Component/Process/Tests/ProcessTest.php
+++ b/src/Symfony/Component/Process/Tests/ProcessTest.php
@@ -48,6 +48,46 @@ class ProcessTest extends TestCase
         }
     }
 
+    /**
+     * @group legacy
+     * @expectedDeprecation The provided cwd does not exist. Command is currently ran against getcwd(). This behavior is deprecated since version 3.4 and will be removed in 4.0.
+     */
+    public function testInvalidCwd()
+    {
+        if ('\\' === DIRECTORY_SEPARATOR) {
+            $this->markTestSkipped('Windows handles this automatically.');
+        }
+
+        // Check that it works fine if the CWD exists
+        $cmd = new Process('echo test', __DIR__);
+        $cmd->run();
+
+        $cmd = new Process('echo test', __DIR__.'/notfound/');
+        $cmd->run();
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Process\Exception\RuntimeException
+     * @expectedExceptionMessage The provided cwd does not exist.
+     */
+    public function testInvalidCwdOnWindows()
+    {
+        if ('\\' !== DIRECTORY_SEPARATOR) {
+            $this->markTestSkipped('Unix handles this automatically.');
+        }
+
+        try {
+            // Check that it works fine if the CWD exists
+            $cmd = new Process('echo test', __DIR__);
+            $cmd->run();
+        } catch (\Exception $e) {
+            $this->fail($e);
+        }
+
+        $cmd = new Process('echo test', __DIR__.'/notfound/');
+        $cmd->run();
+    }
+
     public function testThatProcessDoesNotThrowWarningDuringRun()
     {
         if ('\\' === DIRECTORY_SEPARATOR) {