diff --git a/Input/ArrayInput.php b/Input/ArrayInput.php
index 66f0bedc3..5c1e2f63a 100644
--- a/Input/ArrayInput.php
+++ b/Input/ArrayInput.php
@@ -108,12 +108,13 @@ public function __toString()
         $params = [];
         foreach ($this->parameters as $param => $val) {
             if ($param && \is_string($param) && '-' === $param[0]) {
+                $glue = ('-' === $param[1]) ? '=' : ' ';
                 if (\is_array($val)) {
                     foreach ($val as $v) {
-                        $params[] = $param.('' != $v ? '='.$this->escapeToken($v) : '');
+                        $params[] = $param.('' != $v ? $glue.$this->escapeToken($v) : '');
                     }
                 } else {
-                    $params[] = $param.('' != $val ? '='.$this->escapeToken($val) : '');
+                    $params[] = $param.('' != $val ? $glue.$this->escapeToken($val) : '');
                 }
             } else {
                 $params[] = \is_array($val) ? implode(' ', array_map([$this, 'escapeToken'], $val)) : $this->escapeToken($val);
diff --git a/Tests/Input/ArrayInputTest.php b/Tests/Input/ArrayInputTest.php
index f3eedb3a2..5777c44b7 100644
--- a/Tests/Input/ArrayInputTest.php
+++ b/Tests/Input/ArrayInputTest.php
@@ -162,10 +162,10 @@ public function provideInvalidInput()
     public function testToString()
     {
         $input = new ArrayInput(['-f' => null, '-b' => 'bar', '--foo' => 'b a z', '--lala' => null, 'test' => 'Foo', 'test2' => "A\nB'C"]);
-        $this->assertEquals('-f -b=bar --foo='.escapeshellarg('b a z').' --lala Foo '.escapeshellarg("A\nB'C"), (string) $input);
+        $this->assertEquals('-f -b bar --foo='.escapeshellarg('b a z').' --lala Foo '.escapeshellarg("A\nB'C"), (string) $input);
 
         $input = new ArrayInput(['-b' => ['bval_1', 'bval_2'], '--f' => ['fval_1', 'fval_2']]);
-        $this->assertSame('-b=bval_1 -b=bval_2 --f=fval_1 --f=fval_2', (string) $input);
+        $this->assertSame('-b bval_1 -b bval_2 --f=fval_1 --f=fval_2', (string) $input);
 
         $input = new ArrayInput(['array_arg' => ['val_1', 'val_2']]);
         $this->assertSame('val_1 val_2', (string) $input);