diff --git a/src/Twig/Parser/ContentParser.php b/src/Twig/Parser/ContentParser.php
index 426e3f72..d02ec1e3 100644
--- a/src/Twig/Parser/ContentParser.php
+++ b/src/Twig/Parser/ContentParser.php
@@ -82,15 +82,9 @@ private function callFunction(
         array $arguments,
     ): string {
         Assert::keyExists($functions, $functionName, sprintf('Function %s does not exist!', $functionName));
-        /** @var TwigFunction $function */
-        $function = $functions[$functionName];
-        $callable = $function->getCallable();
-        Assert::isArray($callable, sprintf('Function with name "%s" is not callable', $functionName));
-        $extension = $callable[0];
-        $extensionMethod = $callable[1];
-        $callback = [$extension, $extensionMethod];
-        Assert::isCallable($callback);
-
-        return call_user_func_array($callback, $arguments);
+        $callable = $functions[$functionName]->getCallable();
+        Assert::isCallable($callable, sprintf('Function with name "%s" is not callable', $functionName));
+
+        return call_user_func_array($callable, $arguments);
     }
 }
diff --git a/tests/Unit/Twig/Parser/ContentParserTest.php b/tests/Unit/Twig/Parser/ContentParserTest.php
index bb97c63b..f8a733fa 100644
--- a/tests/Unit/Twig/Parser/ContentParserTest.php
+++ b/tests/Unit/Twig/Parser/ContentParserTest.php
@@ -82,4 +82,56 @@ public function testParsesStringFunctions(): void
 
         self::assertSame("Let's render! parsed\nLet's render twice! parsed2", $this->contentParser->parse($input));
     }
+
+    public function testParsesWithFirstClassCallable(): void
+    {
+        $twigEnvironment = $this->createMock(Environment::class);
+        $twigEnvironment
+            ->method('getFunctions')
+            ->willReturn([
+                'app_render_gallery' => new TwigFunction('app_render_gallery', $this->renderGallery(...)),
+            ])
+        ;
+
+        $contentParser = new ContentParser($twigEnvironment, ['app_render_gallery']);
+
+        self::assertSame(
+            'gallery: summer',
+            $contentParser->parse("{{ app_render_gallery('summer') }}"),
+        );
+    }
+
+    public function testSkipsDisabledFunction(): void
+    {
+        $this->renderBlockRuntime
+            ->expects(self::never())
+            ->method('renderBlock')
+        ;
+
+        $contentParser = new ContentParser($this->twigEnvironment, []);
+        $input = "{{ sylius_cms_render_block('intro') }}";
+
+        self::assertSame($input, $contentParser->parse($input));
+    }
+
+    public function testReplacesWithEmptyStringWhenFunctionNotRegisteredInTwig(): void
+    {
+        $twigEnvironment = $this->createMock(Environment::class);
+        $twigEnvironment
+            ->method('getFunctions')
+            ->willReturn([])
+        ;
+
+        $contentParser = new ContentParser($twigEnvironment, ['sylius_cms_render_block']);
+
+        self::assertSame(
+            '',
+            $contentParser->parse("{{ sylius_cms_render_block('intro') }}"),
+        );
+    }
+
+    private function renderGallery(string $slug): string
+    {
+        return sprintf('gallery: %s', $slug);
+    }
 }