diff --git a/composer.json b/composer.json
index ca9433f..9588a16 100644
--- a/composer.json
+++ b/composer.json
@@ -20,8 +20,8 @@
         "protobuf-php/google-protobuf-proto" : ">=0.1",
         "zendframework/zend-code"            : "^2.6",
         "psr/log"                            : "^1.0",
-        "symfony/console"                    : "^2.5|^3.0",
-        "symfony/process"                    : "^2.5|^3.0",
+        "symfony/console"                    : "^2.5|^3.0|^4.0",
+        "symfony/process"                    : "^2.5|^3.0|^4.0",
         "doctrine/inflector"                 : "^1.0"
     },
     "require-dev": {
diff --git a/src/Protoc/ProcessBuilder.php b/src/Protoc/ProcessBuilder.php
index a7e3bc6..cd9c0af 100644
--- a/src/Protoc/ProcessBuilder.php
+++ b/src/Protoc/ProcessBuilder.php
@@ -7,7 +7,6 @@
 use InvalidArgumentException;
 use UnexpectedValueException;
 use Symfony\Component\Process\Process;
-use Symfony\Component\Process\ProcessBuilder as SymfonyProcessBuilder;
 
 /**
  * Protoc Process Builder
@@ -115,21 +114,22 @@ public function createProcess($outPath, array $protosFiles, array $includeDirs,
             throw new InvalidArgumentException('Proto file list cannot be empty.');
         }
 
-        $builder = new SymfonyProcessBuilder();
         $outDir  = $this->getRealPath($outPath);
         $include = $this->getRealPaths($includeDirs);
         $protos  = $this->getRealPaths($protosFiles, true);
 
-        $builder->setPrefix($this->protoc);
+        $commandLine = "";
 
-        $builder->add(sprintf('--plugin=protoc-gen-php=%s', $this->plugin));
+        $commandLine .= $this->protoc;
+
+        $commandLine .= " ".sprintf('--plugin=protoc-gen-php=%s', $this->plugin);
 
         foreach ($include as $i) {
-            $builder->add(sprintf('--proto_path=%s', $i));
+            $commandLine .= " ".sprintf('--proto_path=%s', $i);
         }
 
         if ($this->includeDescriptors) {
-            $builder->add(sprintf('--proto_path=%s', $this->findDescriptorsPath()));
+            $commandLine .= " ".sprintf('--proto_path=%s', $this->findDescriptorsPath());
         }
 
         // Protoc will pass custom arguments to the plugin if they are given
@@ -138,14 +138,16 @@ public function createProcess($outPath, array $protosFiles, array $includeDirs,
             ? http_build_query($parameters, '', '&') . ':' . $outDir
             : $outDir;
 
-        $builder->add(sprintf('--php_out=%s', $out));
+        $commandLine .= " ".sprintf('--php_out=%s', $out);
 
         // Add the chosen proto files to generate
         foreach ($protos as $proto) {
-            $builder->add($proto);
+            $commandLine .= " ".$proto;
         }
 
-        return $builder->getProcess();
+        $builder = new Process($commandLine);
+
+        return $builder;
     }
 
     /**