diff --git a/lib/VM.php b/lib/VM.php
index 54c9e7d55..a342b9af6 100755
--- a/lib/VM.php
+++ b/lib/VM.php
@@ -56,19 +56,19 @@ public function run(Block $block): int {
                     break;
                 case OpCode::TYPE_ARRAY_DIM_FETCH:
                     $arg1 = $frame->scope[$op->arg1];
-                    $arg2 = $frame->scope[$op->arg2];
+                    $container = $frame->scope[$op->arg2]->resolveIndirect();
                     if (is_null($op->arg3)) {
-                        if ($arg2->type !== Variable::TYPE_ARRAY) {
+                        if ($container->type !== Variable::TYPE_ARRAY) {
                             throw new \LogicException('[] is only supported for arrays');
                         }
-                        $arg1->indirect($arg2->toArray()->append(new Variable));
+                        $arg1->indirect($container->toArray()->append(new Variable));
                         break;
                     }
                     $arg3 = $frame->scope[$op->arg3];
-                    if ($arg2->type === Variable::TYPE_STRING) {
-                        $arg1->string($arg2->toString()[$arg3->toInt()]);
-                    } elseif ($arg2->type === Variable::TYPE_ARRAY) {
-                        $arg1->indirect($arg2->toArray()->findVariable($arg3, false));
+                    if ($container->type === Variable::TYPE_STRING) {
+                        $arg1->string($container->toString()[$arg3->toInt()]);
+                    } elseif ($container->type === Variable::TYPE_ARRAY) {
+                        $arg1->indirect($container->toArray()->findVariable($arg3, false));
                     } else {
                         throw new \LogicException('Illegal offset');
                     }
diff --git a/lib/Web/Superglobals.php b/lib/Web/Superglobals.php
index 4c1ae939f..670b0aa1a 100644
--- a/lib/Web/Superglobals.php
+++ b/lib/Web/Superglobals.php
@@ -163,11 +163,88 @@ private static function populateFormEncoded(HashTable $ht, string $body): void
         }
         $params = [];
         parse_str($body, $params);
+        self::mergeParsedParams($ht, $params);
+    }
+
+    /**
+     * Merge PHP parse_str() output into a VM hashtable (supports nested keys and lists).
+     *
+     * @param array<int|string, mixed> $params
+     */
+    private static function mergeParsedParams(HashTable $ht, array $params): void
+    {
         foreach ($params as $key => $value) {
-            if (!is_string($key) || is_array($value)) {
+            if (is_array($value)) {
+                $child = self::ensureArrayChild($ht, $key);
+                self::mergeParsedParams($child, $value);
+
+                continue;
+            }
+            if (!is_scalar($value)) {
                 continue;
             }
-            self::setStringEntry($ht, $key, (string) $value);
+            self::setScalarEntry($ht, $key, $value);
+        }
+    }
+
+    /**
+     * @param int|string $key
+     */
+    private static function ensureArrayChild(HashTable $ht, $key): HashTable
+    {
+        $existing = is_int($key) ? $ht->findIndex($key) : $ht->find((string) $key);
+        if (null !== $existing) {
+            $resolved = $existing->resolveIndirect();
+            if (Variable::TYPE_ARRAY === $resolved->type) {
+                return $resolved->toArray();
+            }
+        }
+
+        $nested = new HashTable();
+        $var = new Variable(Variable::TYPE_ARRAY);
+        $var->array($nested);
+        if (null !== $existing) {
+            $existing->copyFrom($var);
+        } elseif (is_int($key)) {
+            $ht->addIndex($key, $var);
+        } else {
+            $ht->add((string) $key, $var);
+        }
+
+        return $nested;
+    }
+
+    /**
+     * @param int|string $key
+     * @param bool|float|int|string $value
+     */
+    private static function setScalarEntry(HashTable $ht, $key, $value): void
+    {
+        $var = new Variable();
+        if (is_int($value)) {
+            $var->int($value);
+        } elseif (is_float($value)) {
+            $var->float($value);
+        } elseif (is_bool($value)) {
+            $var->bool($value);
+        } else {
+            $var->string((string) $value);
+        }
+        if (is_int($key)) {
+            $existing = $ht->findIndex($key);
+            if (null !== $existing) {
+                $existing->copyFrom($var);
+            } else {
+                $ht->addIndex($key, $var);
+            }
+
+            return;
+        }
+        $existing = $ht->find((string) $key);
+        if (null !== $existing) {
+            $existing->copyFrom($var);
+        } else {
+            $ht->add((string) $key, $var);
         }
     }
 
diff --git a/test/real/cases/web_get_array_params.phpt b/test/real/cases/web_get_array_params.phpt
new file mode 100644
index 000000000..41374c094
--- /dev/null
+++ b/test/real/cases/web_get_array_params.phpt
@@ -0,0 +1,11 @@
+--TEST--
+Web: array query parameters (tags[]=a&user[name]=Ada)
+--ENV--
+QUERY_STRING=tags[]=a&tags[]=b&user[name]=Ada
+--FILE--
+<?php
+echo implode(',', $_GET['tags']), "\n";
+echo $_GET['user']['name'], "\n";
+--EXPECT--
+a,b
+Ada
diff --git a/test/unit/Web/SuperglobalsArrayParamsTest.php b/test/unit/Web/SuperglobalsArrayParamsTest.php
new file mode 100644
index 000000000..cfe9dca56
--- /dev/null
+++ b/test/unit/Web/SuperglobalsArrayParamsTest.php
@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPCompiler;
+
+use PHPCompiler\VM\Variable as VMVariable;
+use PHPCompiler\Web\Superglobals;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Issue #200: parse_str-style nested $_GET / $_POST population.
+ */
+final class SuperglobalsArrayParamsTest extends TestCase
+{
+    public function testNestedAndListQueryParameters(): void
+    {
+        $runtime = new Runtime();
+        Superglobals::populateFromEnvironment(
+            $runtime->vmContext,
+            'tags[]=a&tags[]=b&user[name]=Ada',
+            ''
+        );
+
+        $get = $runtime->vmContext->getSuperglobal('_GET');
+        $this->assertNotNull($get);
+        $table = $get->toArray();
+
+        $tagsKey = new VMVariable();
+        $tagsKey->string('tags');
+        $this->assertTrue($table->offsetIsSet($tagsKey));
+        $tags = $table->find('tags')->resolveIndirect()->toArray();
+
+        $zero = new VMVariable();
+        $zero->int(0);
+        $one = new VMVariable();
+        $one->int(1);
+        $this->assertTrue($tags->offsetIsSet($zero));
+        $this->assertTrue($tags->offsetIsSet($one));
+        $this->assertSame('a', $tags->findIndex(0)->resolveIndirect()->toString());
+        $this->assertSame('b', $tags->findIndex(1)->resolveIndirect()->toString());
+
+        $userKey = new VMVariable();
+        $userKey->string('user');
+        $this->assertTrue($table->offsetIsSet($userKey));
+        $user = $table->find('user')->resolveIndirect()->toArray();
+
+        $nameKey = new VMVariable();
+        $nameKey->string('name');
+        $this->assertTrue($user->offsetIsSet($nameKey));
+        $this->assertSame('Ada', $user->find('name')->resolveIndirect()->toString());
+    }
+
+    public function testNestedPostBody(): void
+    {
+        $runtime = new Runtime();
+        Superglobals::populateFromEnvironment(
+            $runtime->vmContext,
+            '',
+            'items[]=x&items[]=y&meta[ok]=1'
+        );
+
+        $post = $runtime->vmContext->getSuperglobal('_POST');
+        $this->assertNotNull($post);
+        $table = $post->toArray();
+
+        $items = $table->find('items')->resolveIndirect()->toArray();
+        $this->assertSame('x', $items->findIndex(0)->resolveIndirect()->toString());
+        $this->assertSame('y', $items->findIndex(1)->resolveIndirect()->toString());
+
+        $meta = $table->find('meta')->resolveIndirect()->toArray();
+        $this->assertSame('1', $meta->find('ok')->resolveIndirect()->toString());
+    }
+}