diff --git a/src/__tests__/runBatch.ts b/src/__tests__/runBatch.ts
index f88c2f23..d4166076 100644
--- a/src/__tests__/runBatch.ts
+++ b/src/__tests__/runBatch.ts
@@ -28,6 +28,7 @@ const replacedImports: CliOptions['replaceImports'] = {
 };
 const compilerOptions = {
   baseUrl: baseDir,
+  strictNullChecks: true,
   paths: {
     '#specimens/*': ['specimens/'],
   },
diff --git a/src/__tests__/specimens/byType/CallExpressionModule.php b/src/__tests__/specimens/byType/CallExpressionModule.php
index 0f3a50ec..5a0d7026 100644
--- a/src/__tests__/specimens/byType/CallExpressionModule.php
+++ b/src/__tests__/specimens/byType/CallExpressionModule.php
@@ -17,7 +17,7 @@ public static function getInstance(): CallExpressionModule {
     }
 
     /**
-     * @var mixed[] $c
+     * @var mixed|mixed[] $c
      */
     public $c;
 
diff --git a/src/__tests__/specimens/components/BasicComponentWithProps.tsx b/src/__tests__/specimens/components/BasicComponentWithProps.tsx
index 40b5d197..0e1d66e9 100644
--- a/src/__tests__/specimens/components/BasicComponentWithProps.tsx
+++ b/src/__tests__/specimens/components/BasicComponentWithProps.tsx
@@ -4,6 +4,7 @@ const {useState} = React;
 
 interface Props {
   count: number;
+  actionText?: string;
   handleScroll: () => void;
 }
 
@@ -12,14 +13,14 @@ interface Props {
  * @param props
  * @constructor
  */
-export function BasicComponentWithProps({count: cnt, handleScroll}: Props) {
+export function BasicComponentWithProps({count: cnt, actionText, handleScroll}: Props) {
   const [count, setCount] = useState(cnt);
 
   return (
     <div onScroll={handleScroll}>
       <p>You clicked {count} times starting at {cnt}.</p>
       <button onClick={() => setCount(count + 1)}>
-        Click me
+        {actionText || 'Click me'}
       </button>
     </div>
   );
diff --git a/src/__tests__/specimens/components/BasicComponentWithProps/BasicComponentWithProps.php b/src/__tests__/specimens/components/BasicComponentWithProps/BasicComponentWithProps.php
index ce1b1f1b..1a56a832 100644
--- a/src/__tests__/specimens/components/BasicComponentWithProps/BasicComponentWithProps.php
+++ b/src/__tests__/specimens/components/BasicComponentWithProps/BasicComponentWithProps.php
@@ -26,6 +26,7 @@ private function __construct() {
      */
     public function render(array $anon_deref_1, array $children) {
         $cnt = (float) $anon_deref_1["count"];
+        $action_text = $anon_deref_1["actionText"];
         $anon_2c03773 = [$cnt];
         $count = (float) $anon_2c03773[0];
         return \VK\Elephize\Builtins\IntrinsicElement::get("div")->render(
@@ -35,7 +36,10 @@ public function render(array $anon_deref_1, array $children) {
                     [],
                     ["You clicked ", $count, " times starting at ", $cnt, "."]
                 ),
-                \VK\Elephize\Builtins\IntrinsicElement::get("button")->render([], [" Click me "]),
+                \VK\Elephize\Builtins\IntrinsicElement::get("button")->render(
+                    [],
+                    [\VK\Elephize\Builtins\IntrinsicElement::escape($action_text ?: "Click me")]
+                ),
             ]
         );
     }
diff --git a/src/__tests__/specimens/components/ComponentBinaryOperators/ComponentBinaryOperators.php b/src/__tests__/specimens/components/ComponentBinaryOperators/ComponentBinaryOperators.php
index 75b7d5ec..107bd2c8 100644
--- a/src/__tests__/specimens/components/ComponentBinaryOperators/ComponentBinaryOperators.php
+++ b/src/__tests__/specimens/components/ComponentBinaryOperators/ComponentBinaryOperators.php
@@ -35,12 +35,14 @@ public function render(array $props, array $children) {
                     ["You clicked ", $props["count"], " times"]
                 ),
                 \VK\Elephize\Builtins\IntrinsicElement::get("button")->render([], [" Click me "]),
-                $input_value
-                    ? \VK\Elephize\Builtins\IntrinsicElement::get("span")->render(
-                        ["className" => "someSpan"],
-                        [\VK\Elephize\Builtins\IntrinsicElement::escape($input_value)]
-                    )
-                    : $input_value,
+                \VK\Elephize\Builtins\IntrinsicElement::escape(
+                    $input_value
+                        ? \VK\Elephize\Builtins\IntrinsicElement::get("span")->render(
+                            ["className" => "someSpan"],
+                            [\VK\Elephize\Builtins\IntrinsicElement::escape($input_value)]
+                        )
+                        : $input_value
+                ),
             ]
         );
     }
diff --git a/src/__tests__/specimens/components/InheritedProps/InheritedProps.php b/src/__tests__/specimens/components/InheritedProps/InheritedProps.php
index f27fc1de..17e12097 100644
--- a/src/__tests__/specimens/components/InheritedProps/InheritedProps.php
+++ b/src/__tests__/specimens/components/InheritedProps/InheritedProps.php
@@ -44,12 +44,14 @@ public function render(array $input_props, array $children) {
                     []
                 ),
                 \VK\Elephize\Builtins\IntrinsicElement::get("span")->render(["className" => "Radio__control"], []),
-                $children
-                    ? \VK\Elephize\Builtins\IntrinsicElement::get("span")->render(
-                        ["className" => "Radio__text"],
-                        [\VK\Elephize\Builtins\IntrinsicElement::escape($children)]
-                    )
-                    : $children,
+                \VK\Elephize\Builtins\IntrinsicElement::escape(
+                    $children
+                        ? \VK\Elephize\Builtins\IntrinsicElement::get("span")->render(
+                            ["className" => "Radio__text"],
+                            [\VK\Elephize\Builtins\IntrinsicElement::escape($children)]
+                        )
+                        : $children
+                ),
             ]
         );
     }
diff --git a/src/__tests__/specimens/fixes/CheckBox/CheckBox.php b/src/__tests__/specimens/fixes/CheckBox/CheckBox.php
index df28f71d..4ec0b35c 100644
--- a/src/__tests__/specimens/fixes/CheckBox/CheckBox.php
+++ b/src/__tests__/specimens/fixes/CheckBox/CheckBox.php
@@ -26,7 +26,7 @@ private function __construct() {
      */
     public function render(array $props, array $children) {
         $checked = $props["checked"];
-        $disabled = (bool) $props["disabled"];
+        $disabled = $props["disabled"];
         $name = $props["name"];
         $id = $props["id"];
         $native_props = Stdlib::objectOmit($props, ["children", "checked", "disabled", "indeterminate", "name", "id"]);
@@ -44,7 +44,7 @@ public function render(array $props, array $children) {
                         "type" => "checkbox",
                         "checked" => !!$checked,
                         "name" => \VK\Elephize\Builtins\IntrinsicElement::escape((string) $name),
-                        "disabled" => $disabled,
+                        "disabled" => \VK\Elephize\Builtins\IntrinsicElement::escape($disabled),
                     ]),
                     []
                 ),
diff --git a/src/__tests__/specimens/fixes/ExcessiveEscaping/TextContainer.php b/src/__tests__/specimens/fixes/ExcessiveEscaping/TextContainer.php
index 6c6cef3e..9cc89091 100644
--- a/src/__tests__/specimens/fixes/ExcessiveEscaping/TextContainer.php
+++ b/src/__tests__/specimens/fixes/ExcessiveEscaping/TextContainer.php
@@ -25,7 +25,7 @@ private function __construct() {
      * @return ?string
      */
     public function render(array $anon_deref_1, array $children) {
-        $align = (string) $anon_deref_1["align"];
+        $align = $anon_deref_1["align"];
         $class_names = ["content-text--container"];
         if ($align) {
             array_push($class_names, "content-text--container__align-" . $align);
diff --git a/src/__tests__/watcherTestEnv.ts b/src/__tests__/watcherTestEnv.ts
index 5308fbb0..22cdc34e 100644
--- a/src/__tests__/watcherTestEnv.ts
+++ b/src/__tests__/watcherTestEnv.ts
@@ -26,6 +26,7 @@ const ignoreImportRules: Set<string> = new Set();
 const replaceImportRules = { };
 const compilerOptions = {
   baseUrl: baseDir,
+  strictNullChecks: true,
   paths: {
     '#specimens/*': ['specimens'],
   },
diff --git a/src/ts2php/components/cli/transpile.ts b/src/ts2php/components/cli/transpile.ts
index 2a498ebe..8e526813 100644
--- a/src/ts2php/components/cli/transpile.ts
+++ b/src/ts2php/components/cli/transpile.ts
@@ -64,6 +64,7 @@ export function transpile(options: CliOptions, baseDir: string, outDir: string,
     const compilerOptions = {
       baseUrl: baseDir,
       paths: options.tsPaths || {},
+      strictNullChecks: true,
     };
 
     (options.watch ? translateCodeAndWatch : translateCode)(
diff --git a/src/ts2php/components/codegen/defaultCompilerOptions.ts b/src/ts2php/components/codegen/defaultCompilerOptions.ts
index 5748978c..07e3e6b4 100644
--- a/src/ts2php/components/codegen/defaultCompilerOptions.ts
+++ b/src/ts2php/components/codegen/defaultCompilerOptions.ts
@@ -18,4 +18,5 @@ export const defaultCompilerOptions: ts.CompilerOptions = {
   allowUnreachableCode: true,
   allowJs: true,
   resolveJsonModule: true,
+  strictNullChecks: true,
 };
diff --git a/src/ts2php/components/typeInference/basicTypes.ts b/src/ts2php/components/typeInference/basicTypes.ts
index a6f10dde..7dc8e103 100644
--- a/src/ts2php/components/typeInference/basicTypes.ts
+++ b/src/ts2php/components/typeInference/basicTypes.ts
@@ -257,7 +257,7 @@ const transformTypeName = (type: ts.Type, node: ts.Node, checker: ts.TypeChecker
 
 function describeNodeType(node: ts.Node | undefined, type: ts.Type, checker: ts.TypeChecker, log: LogObj) {
   const nodeIdentForLog = node?.getText();
-  const optionalMark = (node?.parent.kind === ts.SyntaxKind.Parameter && (
+  let optionalMark = (node?.parent.kind === ts.SyntaxKind.Parameter && (
     (node.parent as ts.ParameterDeclaration).initializer ||
     (node.parent as ts.ParameterDeclaration).questionToken
   )) ? '?' : '';
@@ -274,16 +274,32 @@ function describeNodeType(node: ts.Node | undefined, type: ts.Type, checker: ts.
 
   const customTypehints = checkCustomTypehints(type, checker);
   if (customTypehints) {
-    const types = customTypehints.foundTypes.map((t) => {
-      if (typeof t === 'string') {
-        return optionalMark + t;
-      }
-      // Some of union members may be literal types
-      return optionalMark + describeAsApparentType(t, node!, checker, log, nodeIdentForLog);
-    }).filter((t) => !customTypehints.typesToDrop.includes(t));
-    const typehint = Array.from(new Set((<string[]>[])
-      .concat(types)))
-      .join('|');
+    if (!optionalMark) {
+      optionalMark = customTypehints.foundTypes.find(
+        (t) => typeof t !== 'string' && t.getFlags() & ts.TypeFlags.Undefined
+      )
+        ? '?'
+        : '';
+    }
+
+    const types = customTypehints.foundTypes
+      .filter(
+        (t) => typeof t === 'string' || !(t.getFlags() & ts.TypeFlags.Undefined)
+      )
+      .map((t) => {
+        if (typeof t === 'string') {
+          return optionalMark + t;
+        }
+        // Some of union members may be literal types
+        return (
+          optionalMark +
+          describeAsApparentType(t, node!, checker, log, nodeIdentForLog)
+        );
+      })
+      .filter((t) => !customTypehints.typesToDrop.includes(t));
+    const typehint = Array.from(new Set((<string[]>[]).concat(types))).join(
+      '|'
+    );
     log.typehint('Inferred type of node: %s -> %s [1]', [nodeIdentForLog || '', typehint]);
     return typehint;
   }