diff --git a/src/Writers/FunctionWriter.php b/src/Writers/FunctionWriter.php
index 0fafd93..024608b 100644
--- a/src/Writers/FunctionWriter.php
+++ b/src/Writers/FunctionWriter.php
@@ -5,6 +5,7 @@
 use Closure;
 use PhpParser\Node\Arg;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Cast\Int_ as IntCast;
 use PhpParser\Node\Expr\ConstFetch;
 use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Name;
@@ -85,6 +86,11 @@ public function closure(Closure $closure)
         return $closure;
     }
 
+    public function castInt(Expr $expr): IntCast
+    {
+        return new IntCast($expr);
+    }
+
     private function convertToArgs($args)
     {
         return collect($args)
diff --git a/src/Writers/TypeWriter.php b/src/Writers/TypeWriter.php
index aaa7e6b..562031f 100644
--- a/src/Writers/TypeWriter.php
+++ b/src/Writers/TypeWriter.php
@@ -5,10 +5,10 @@
 use Closure;
 use Exception;
 use Laravel\SerializableClosure\Support\ReflectionClosure;
+use PhpParser\Node\Expr;
 use PhpParser\Node\Expr\Array_;
 use PhpParser\Node\Expr\Cast\Bool_;
 use PhpParser\Node\Expr\Cast\Int_;
-use PhpParser\Node\Expr\FuncCall;
 use PhpParser\Node\Scalar\String_;
 use Stillat\Proteus\Analyzers\TypeAnalyzer;
 use Stillat\Proteus\Analyzers\Types;
@@ -40,7 +40,7 @@ public static function write($value)
             return $closureParser->parse($serialized->getCode());
         }
 
-        if ($value instanceof FuncCall) {
+        if ($value instanceof Expr) {
             return $value;
         }
 
diff --git a/tests/LaravelFunctionCallTest.php b/tests/LaravelFunctionCallTest.php
index e7ae1a3..7129139 100644
--- a/tests/LaravelFunctionCallTest.php
+++ b/tests/LaravelFunctionCallTest.php
@@ -116,6 +116,19 @@ public function testFunctionCallsCanBeNestedAsArguments()
         );
     }
 
+    public function testCastIntCanBeWritten()
+    {
+        $f = new FunctionWriter();
+
+        $this->assertChangeEquals(
+            __DIR__.'/configs/empty.php',
+            __DIR__.'/expected/castint.php',
+            [
+                'thing' => $f->castInt($f->env('KEY', 20)),
+            ]
+        );
+    }
+
     public function testWritingNewClosuresOrArrowFunctions()
     {
         $f = new FunctionWriter();
diff --git a/tests/expected/castint.php b/tests/expected/castint.php
new file mode 100644
index 0000000..ca7d9a7
--- /dev/null
+++ b/tests/expected/castint.php
@@ -0,0 +1,5 @@
+<?php
+
+return [
+    'thing' => (int) env('KEY', 20),
+];