diff --git a/Decoder/JsonToFormDecoder.php b/Decoder/JsonToFormDecoder.php
index 7b6b8ef46..a801fa091 100644
--- a/Decoder/JsonToFormDecoder.php
+++ b/Decoder/JsonToFormDecoder.php
@@ -46,7 +46,7 @@ private function xWwwFormEncodedLike(array &$data): void
     public function decode(string $data)
     {
         $decodedData = @json_decode($data, true);
-        if ($decodedData) {
+        if (is_array($decodedData)) {
             $this->xWwwFormEncodedLike($decodedData);
         }
 
diff --git a/Tests/Decoder/JsonToFormDecoderTest.php b/Tests/Decoder/JsonToFormDecoderTest.php
index 5133225cf..0d6360158 100644
--- a/Tests/Decoder/JsonToFormDecoderTest.php
+++ b/Tests/Decoder/JsonToFormDecoderTest.php
@@ -47,4 +47,12 @@ public function testDecodeWithRemovingFalseData()
         $this->assertEquals('3.14', $decoded['floatKey']);
         $this->assertEquals('bar', $decoded['stringKey']);
     }
+
+    public function testDecodeStringData()
+    {
+        $decoder = new JsonToFormDecoder();
+        $decoded = $decoder->decode('"foo"');
+
+        $this->assertSame('foo', $decoded);
+    }
 }