diff --git a/src/Builder/BuilderInterface.php b/src/Builder/BuilderInterface.php
index e4b7a41..d3ca112 100644
--- a/src/Builder/BuilderInterface.php
+++ b/src/Builder/BuilderInterface.php
@@ -49,7 +49,7 @@ function getDefaultTemplateName(): string;
      *
      * @return string   The short classname.
      */
-    function getSimpleClassName(string $class = null): string;
+    function getSimpleClassName(?string $class = null): string;
 
     function setOutputName(string $outputName): void;
 
diff --git a/src/Builder/Generator.php b/src/Builder/Generator.php
index a12fdce..b51de61 100644
--- a/src/Builder/Generator.php
+++ b/src/Builder/Generator.php
@@ -41,7 +41,7 @@ class Generator
      *
      * @param string|null $baseTempDir Existing base directory for temporary template files
      */
-    public function __construct(string $baseTempDir = null)
+    public function __construct(?string $baseTempDir = null)
     {
         if (null === $baseTempDir) {
             $baseTempDir = sys_get_temp_dir();
diff --git a/src/Extension/TwigPrintExtension.php b/src/Extension/TwigPrintExtension.php
index 86236f4..106ca4f 100644
--- a/src/Extension/TwigPrintExtension.php
+++ b/src/Extension/TwigPrintExtension.php
@@ -28,8 +28,6 @@ public function getFunctions(): array
             'echo_endfor'         => new TwigFunction('echo_endfor'      , $this->getEchoEndFor(...), $options),
             'echo_raw'            => new TwigFunction('echo_raw'         , $this->getEchoRaw(...), $options),
             'echo_endraw'         => new TwigFunction('echo_endraw'      , $this->getEchoEndRaw(...), $options),
-            'echo_spaceless'      => new TwigFunction('echo_spaceless'   , $this->getEchoSpaceless(...), $options),
-            'echo_endspaceless'   => new TwigFunction('echo_endspaceless', $this->getEchoEndSpaceless(...), $options),
             'echo_extends'        => new TwigFunction('echo_extends'     , $this->getEchoExtends(...), $options),
             'echo_if'             => new TwigFunction('echo_if'          , $this->getEchoIf(...), $options),
             'echo_else'           => new TwigFunction('echo_else'        , $this->getEchoElse(...), $options),
@@ -188,7 +186,7 @@ public function getEchoExtends(string $name): string
      * {{ echo_for('item', 'myListObject', 'key') }}
      *      => {% for key,item in myListObject %}
      */
-    public function getEchoFor(string $object, string $in, string $key = null): string
+    public function getEchoFor(string $object, string $in, ?string $key = null): string
     {
         return strtr(
             '{% for %%key%%%%object%% in %%in%% %}',
@@ -223,22 +221,6 @@ public function getEchoEndRaw(): string
         return '{% endraw %}';
     }
 
-    /**
-     * Print "spaceless" tag
-     */
-    public function getEchoSpaceless(): string
-    {
-        return '{% apply spaceless %}';
-    }
-
-    /**
-     * Print "endspaceless" tag
-     */
-    public function getEchoEndSpaceless(): string
-    {
-        return '{% endapply %}';
-    }
-
     /**
      * Converts an array to a twig array expression (string).
      * Only in case a value contains '{{' and '}}' the value won't be