diff --git a/bin/functionMetadata_original.php b/bin/functionMetadata_original.php
index 17be4631a9..518986c6b1 100644
--- a/bin/functionMetadata_original.php
+++ b/bin/functionMetadata_original.php
@@ -28,6 +28,7 @@
 	'array_key_last' => ['hasSideEffects' => false],
 	'array_key_exists' => ['hasSideEffects' => false],
 	'array_keys' => ['hasSideEffects' => false],
+	'array_map' => ['hasSideEffects' => false],
 	'array_merge' => ['hasSideEffects' => false],
 	'array_merge_recursive' => ['hasSideEffects' => false],
 	'array_pad' => ['hasSideEffects' => false],
diff --git a/resources/functionMetadata.php b/resources/functionMetadata.php
index a01a7181a6..25ba9d8f87 100644
--- a/resources/functionMetadata.php
+++ b/resources/functionMetadata.php
@@ -737,6 +737,7 @@
 	'array_key_last' => ['hasSideEffects' => false],
 	'array_keys' => ['hasSideEffects' => false],
 	'array_last' => ['hasSideEffects' => false],
+	'array_map' => ['hasSideEffects' => false],
 	'array_merge' => ['hasSideEffects' => false],
 	'array_merge_recursive' => ['hasSideEffects' => false],
 	'array_pad' => ['hasSideEffects' => false],
diff --git a/tests/PHPStan/Rules/Pure/PureMethodRuleTest.php b/tests/PHPStan/Rules/Pure/PureMethodRuleTest.php
index 0aa586868e..22a040b3d8 100644
--- a/tests/PHPStan/Rules/Pure/PureMethodRuleTest.php
+++ b/tests/PHPStan/Rules/Pure/PureMethodRuleTest.php
@@ -279,6 +279,13 @@ public function testAllMethodsArePure(): void
 		]);
 	}
 
+	#[RequiresPhp('>= 8.0')]
+	public function testBug11100(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-11100.php'], []);
+	}
+
 	public function testBug12382(): void
 	{
 		$this->treatPhpDocTypesAsCertain = true;
diff --git a/tests/PHPStan/Rules/Pure/data/bug-11100.php b/tests/PHPStan/Rules/Pure/data/bug-11100.php
new file mode 100644
index 0000000000..537c27b15a
--- /dev/null
+++ b/tests/PHPStan/Rules/Pure/data/bug-11100.php
@@ -0,0 +1,32 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug11100;
+
+final class FooClass
+{
+	/**
+	 * @param array<string, string|int> $getParams
+	 *
+	 * @phpstan-pure
+	 */
+	public function build(array $getParams, string $trailingSlash, bool $useSlashSeparator): string
+	{
+		if ($getParams === []) {
+			return '';
+		}
+
+		if ($useSlashSeparator) {
+			return '/' . implode('/', array_map(
+				static function (string $key, string|int $value): string {
+					return rawurlencode($key) . '/' . rawurlencode((string) $value);
+				},
+				array_keys($getParams),
+				$getParams
+			)) . $trailingSlash;
+		}
+
+		return $trailingSlash . '?' . http_build_query($getParams);
+	}
+}