diff --git a/src/SPC/builder/unix/library/libaom.php b/src/SPC/builder/unix/library/libaom.php
index d0b7c88c..31c40a0f 100644
--- a/src/SPC/builder/unix/library/libaom.php
+++ b/src/SPC/builder/unix/library/libaom.php
@@ -6,6 +6,8 @@ namespace SPC\builder\unix\library;
 
 use SPC\exception\FileSystemException;
 use SPC\exception\RuntimeException;
+use SPC\toolchain\ToolchainManager;
+use SPC\toolchain\ZigToolchain;
 use SPC\util\executor\UnixCMakeExecutor;
 
 trait libaom
@@ -16,8 +18,8 @@ trait libaom
      */
     protected function build(): void
     {
-        if (getenv('SPC_LIBC') === 'musl' && str_contains(getenv('CC'), 'zig')) {
-            f_putenv('COMPILER_EXTRA=-D_POSIX_SOURCE');
+        if (ToolchainManager::getToolchainClass() === ZigToolchain::class) {
+            f_putenv('COMPILER_EXTRA=-D_GNU_SOURCE');
         }
         UnixCMakeExecutor::create($this)
             ->setBuildDir("{$this->source_dir}/builddir")
diff --git a/src/SPC/command/CraftCommand.php b/src/SPC/command/CraftCommand.php
index 84080205..5a40a25d 100644
--- a/src/SPC/command/CraftCommand.php
+++ b/src/SPC/command/CraftCommand.php
@@ -5,6 +5,8 @@ declare(strict_types=1);
 namespace SPC\command;
 
 use SPC\exception\ValidationException;
+use SPC\toolchain\ToolchainManager;
+use SPC\toolchain\ZigToolchain;
 use SPC\util\ConfigValidator;
 use Symfony\Component\Console\Attribute\AsCommand;
 use Symfony\Component\Process\Process;
@@ -76,7 +78,7 @@ class CraftCommand extends BuildCommand
             }
         }
         // install zig if requested
-        if (str_contains(getenv('CC'), 'zig')) {
+        if (ToolchainManager::getToolchainClass() === ZigToolchain::class) {
             $retcode = $this->runCommand('install-pkg', 'zig');
             if ($retcode !== 0) {
                 $this->output->writeln('<error>craft zig failed</error>');
diff --git a/src/SPC/doctor/item/ZigCheck.php b/src/SPC/doctor/item/ZigCheck.php
index f5983f1d..ffd9aca5 100644
--- a/src/SPC/doctor/item/ZigCheck.php
+++ b/src/SPC/doctor/item/ZigCheck.php
@@ -47,7 +47,7 @@ class ZigCheck
             'BSD' => 'freebsd',
             default => 'linux',
         };
-        PackageManager::installPackage("musl-toolchain-{$arch}-{$os}");
+        PackageManager::installPackage("zig-{$arch}-{$os}");
         return Zig::isInstalled();
     }
 }