diff --git a/phpunit/code/native-class-global-keyword-case/mixed-case.php b/phpunit/code/native-class-global-keyword-case/mixed-case.php
new file mode 100644
index 00000000..70356bd4
--- /dev/null
+++ b/phpunit/code/native-class-global-keyword-case/mixed-case.php
@@ -0,0 +1,7 @@
+<?php
+
+function initializeCaseSlot(): void
+{
+    GlObAl $caseSlot;
+    $caseSlot = new NativeCaseValue();
+}
diff --git a/phpunit/code/native-class-global-keyword-case/reader.php b/phpunit/code/native-class-global-keyword-case/reader.php
new file mode 100644
index 00000000..eac9b499
--- /dev/null
+++ b/phpunit/code/native-class-global-keyword-case/reader.php
@@ -0,0 +1,13 @@
+<?php
+
+#[Native]
+class NativeCaseValue
+{
+    public int $value = 42;
+}
+
+function readCaseSlot(): int
+{
+    global $caseSlot;
+    return $caseSlot->value;
+}
diff --git a/phpunit/code/native-class-global-keyword-case/uppercase.php b/phpunit/code/native-class-global-keyword-case/uppercase.php
new file mode 100644
index 00000000..d3a5f329
--- /dev/null
+++ b/phpunit/code/native-class-global-keyword-case/uppercase.php
@@ -0,0 +1,7 @@
+<?php
+
+function initializeCaseSlot(): void
+{
+    GLOBAL $caseSlot;
+    $caseSlot = new NativeCaseValue();
+}
diff --git a/phpunit/src/NativeClass/NativeClassValidationTest.php b/phpunit/src/NativeClass/NativeClassValidationTest.php
index ec807ef2..f5009679 100644
--- a/phpunit/src/NativeClass/NativeClassValidationTest.php
+++ b/phpunit/src/NativeClass/NativeClassValidationTest.php
@@ -89,6 +89,41 @@ final class NativeClassValidationTest extends \BaseTest
         self::assertStringNotContainsString('nativeForwardGlobal.attr(', $code);
     }
 
+    /**
+     * @dataProvider nativeGlobalKeywordCaseProvider
+     */
+    public function testDiscoversNativeGlobalSlotWithCaseInsensitiveKeyword(string $writer): void
+    {
+        global $translator;
+
+        $compiler = \TypePhp\CompilerTest::create(TYPEPHP_ROOT_PATH);
+        $translator = $compiler;
+        $directory = dirname(__DIR__, 2) . '/code/native-class-global-keyword-case';
+        $files = [$directory . '/reader.php', $directory . '/' . $writer];
+        $compiler->discoverNativeClassDeclarations($files);
+        foreach ($files as $file) {
+            $compiler->prepareFile($file);
+        }
+        $compiler->discoverNativeGlobalObjects($files);
+        $reader = $compiler->convertFile($files[0]);
+        $compiler->convertFile($files[1]);
+
+        $code = file_get_contents($reader);
+        self::assertIsString($code);
+        self::assertStringContainsString(
+            'php::nativeRequireObject(caseSlot, "NativeCaseValue")->value',
+            $code,
+        );
+    }
+
+    public static function nativeGlobalKeywordCaseProvider(): array
+    {
+        return [
+            'uppercase' => ['uppercase.php'],
+            'mixed case' => ['mixed-case.php'],
+        ];
+    }
+
     public function testRejectsNativeAttributeOnInterface(): void
     {
         $this->expectException(\TypePhp\Exception\SyntaxError::class);
diff --git a/src/Preprocessor.php b/src/Preprocessor.php
index f34b5fb0..5241d60d 100644
--- a/src/Preprocessor.php
+++ b/src/Preprocessor.php
@@ -223,9 +223,8 @@ class Preprocessor extends CompilerBase
                 continue;
             }
             $source = file_get_contents($file);
-            if (is_string($source)
-                && (str_contains($source, 'global') || str_contains($source, '$GLOBALS'))
-            ) {
+            // PHP keywords are case-insensitive; this also includes $GLOBALS accesses.
+            if (is_string($source) && stripos($source, 'global') !== false) {
                 $candidateSources[$file] = $source;
             }
         }