diff --git a/src/Symfony/Component/Console/Command/Command.php b/src/Symfony/Component/Console/Command/Command.php
index f475ad5363..f526b85a03 100644
--- a/src/Symfony/Component/Console/Command/Command.php
+++ b/src/Symfony/Component/Console/Command/Command.php
@@ -36,6 +36,7 @@ class Command
     private $description;
     private $ignoreValidationErrors;
     private $applicationDefinitionMerged;
+    private $applicationDefinitionMergedWithArgs;
     private $code;
     private $synopsis;
     private $helperSet;
@@ -54,6 +55,7 @@ class Command
         $this->definition = new InputDefinition();
         $this->ignoreValidationErrors = false;
         $this->applicationDefinitionMerged = false;
+        $this->applicationDefinitionMergedWithArgs = false;
         $this->aliases = array();
 
         if (null !== $name) {
@@ -277,7 +279,7 @@ class Command
      */
     private function mergeApplicationDefinition($mergeArgs = true)
     {
-        if (null === $this->application || true === $this->applicationDefinitionMerged) {
+        if (null === $this->application || (true === $this->applicationDefinitionMerged && ($this->applicationDefinitionMergedWithArgs || !$mergeArgs))) {
             return;
         }
 
@@ -290,6 +292,9 @@ class Command
         $this->definition->addOptions($this->application->getDefinition()->getOptions());
 
         $this->applicationDefinitionMerged = true;
+        if ($mergeArgs) {
+            $this->applicationDefinitionMergedWithArgs = true;
+        }
     }
 
     /**
diff --git a/src/Symfony/Component/Console/Tests/Command/CommandTest.php b/src/Symfony/Component/Console/Tests/Command/CommandTest.php
index 166ce7879e..8300f8dfe3 100644
--- a/src/Symfony/Component/Console/Tests/Command/CommandTest.php
+++ b/src/Symfony/Component/Console/Tests/Command/CommandTest.php
@@ -193,6 +193,29 @@ class CommandTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals(3, $command->getDefinition()->getArgumentCount(), '->mergeApplicationDefinition() does not try to merge twice the application arguments and options');
     }
 
+    public function testMergeApplicationDefinitionWithoutArgsThenWithArgsAddsArgs()
+    {
+        $application1 = new Application();
+        $application1->getDefinition()->addArguments(array(new InputArgument('foo')));
+        $application1->getDefinition()->addOptions(array(new InputOption('bar')));
+        $command = new \TestCommand();
+        $command->setApplication($application1);
+        $command->setDefinition($definition = new InputDefinition(array()));
+
+        $r = new \ReflectionObject($command);
+        $m = $r->getMethod('mergeApplicationDefinition');
+        $m->setAccessible(true);
+        $m->invoke($command, false);
+        $this->assertTrue($command->getDefinition()->hasOption('bar'), '->mergeApplicationDefinition(false) merges the application and the commmand options');
+        $this->assertFalse($command->getDefinition()->hasArgument('foo'), '->mergeApplicationDefinition(false) does not merge the application arguments');
+
+        $m->invoke($command, true);
+        $this->assertTrue($command->getDefinition()->hasArgument('foo'), '->mergeApplicationDefinition(true) merges the application arguments and the command arguments');
+
+        $m->invoke($command);
+        $this->assertEquals(2, $command->getDefinition()->getArgumentCount(), '->mergeApplicationDefinition() does not try to merge twice the application arguments');
+    }
+
     public function testRun()
     {
         $command = new \TestCommand();