diff --git a/src/Package/Extension/zlib.php b/src/Package/Extension/zlib.php
index 14ab656d..d04c00a0 100644
--- a/src/Package/Extension/zlib.php
+++ b/src/Package/Extension/zlib.php
@@ -8,15 +8,16 @@ use Package\Target\php;
 use StaticPHP\Attribute\Package\CustomPhpConfigureArg;
 use StaticPHP\Attribute\Package\Extension;
 use StaticPHP\Package\PackageBuilder;
+use StaticPHP\Package\PackageInstaller;
 
 #[Extension('zlib')]
 class zlib
 {
     #[CustomPhpConfigureArg('Darwin')]
     #[CustomPhpConfigureArg('Linux')]
-    public function unixConfigureArg(PackageBuilder $builder): string
+    public function unixConfigureArg(PackageBuilder $builder, PackageInstaller $installer): string
     {
-        $zlib_dir = php::getPHPVersionID() >= 80400 ? '' : ' --with-zlib-dir=' . $builder->getBuildRootPath();
-        return '--with-zlib' . $zlib_dir;
+        $zlib_dir = (php::getPHPVersionID() >= 80400 && !$installer->getPhpExtensionPackage('spx')) ? '' : " --with-zlib-dir={$builder->getBuildRootPath()}";
+        return "--with-zlib{$zlib_dir}";
     }
 }