diff --git a/src/SPC/builder/Extension.php b/src/SPC/builder/Extension.php
index 60cc3708..63dc31d0 100644
--- a/src/SPC/builder/Extension.php
+++ b/src/SPC/builder/Extension.php
@@ -11,6 +11,9 @@ use SPC\exception\ValidationException;
 use SPC\exception\WrongUsageException;
 use SPC\store\Config;
 use SPC\store\FileSystem;
+use SPC\toolchain\ToolchainManager;
+use SPC\toolchain\ZigToolchain;
+use SPC\util\GlobalEnvManager;
 use SPC\util\SPCConfigUtil;
 use SPC\util\SPCTarget;
 
@@ -543,6 +546,11 @@ class Extension
      */
     protected function getSharedExtensionEnv(): array
     {
+        $compiler_extra = getenv('SPC_COMPILER_EXTRA') ?: '';
+        if (!str_contains($compiler_extra, '-lcompiler_rt') && ToolchainManager::getToolchainClass() === ZigToolchain::class) {
+            $compiler_extra = trim($compiler_extra . ' -lcompiler_rt');
+            GlobalEnvManager::putenv("SPC_COMPILER_EXTRA={$compiler_extra}");
+        }
         $config = (new SPCConfigUtil($this->builder, ['no_php' => true]))->getExtensionConfig($this);
         [$staticLibs, $sharedLibs] = $this->splitLibsIntoStaticAndShared($config['libs']);
         $preStatic = PHP_OS_FAMILY === 'Darwin' ? '' : '-Wl,--start-group ';
diff --git a/src/SPC/builder/linux/LinuxBuilder.php b/src/SPC/builder/linux/LinuxBuilder.php
index ffc034a7..ed26d64f 100644
--- a/src/SPC/builder/linux/LinuxBuilder.php
+++ b/src/SPC/builder/linux/LinuxBuilder.php
@@ -11,6 +11,8 @@ use SPC\store\Config;
 use SPC\store\DirDiff;
 use SPC\store\FileSystem;
 use SPC\store\SourcePatcher;
+use SPC\toolchain\ToolchainManager;
+use SPC\toolchain\ZigToolchain;
 use SPC\util\GlobalEnvManager;
 use SPC\util\SPCConfigUtil;
 use SPC\util\SPCTarget;
@@ -267,6 +269,11 @@ class LinuxBuilder extends UnixBuilderBase
      */
     protected function buildEmbed(): void
     {
+        $compiler_extra = getenv('SPC_COMPILER_EXTRA') ?: '';
+        if (!str_contains($compiler_extra, '-lcompiler_rt') && ToolchainManager::getToolchainClass() === ZigToolchain::class) {
+            $compiler_extra = trim($compiler_extra . ' -lcompiler_rt');
+            GlobalEnvManager::putenv("SPC_COMPILER_EXTRA={$compiler_extra}");
+        }
         $sharedExts = array_filter($this->exts, static fn ($ext) => $ext->isBuildShared());
         $sharedExts = array_filter($sharedExts, static function ($ext) {
             return Config::getExt($ext->getName(), 'build-with-php') === true;
diff --git a/src/SPC/toolchain/ZigToolchain.php b/src/SPC/toolchain/ZigToolchain.php
index 6ff67769..1b7cc70d 100644
--- a/src/SPC/toolchain/ZigToolchain.php
+++ b/src/SPC/toolchain/ZigToolchain.php
@@ -64,12 +64,6 @@ class ZigToolchain implements ToolchainInterface
             $extra_libs = trim($extra_libs . ' -lunwind');
             GlobalEnvManager::putenv("SPC_EXTRA_LIBS={$extra_libs}");
         }
-        $compiler_extra = getenv('SPC_COMPILER_EXTRA') ?: '';
-        if (!str_contains($compiler_extra, '-lcompiler_rt')) {
-            // Add unwind library if not already present
-            $compiler_extra = trim($compiler_extra . ' -lcompiler_rt');
-            GlobalEnvManager::putenv("SPC_COMPILER_EXTRA={$compiler_extra}");
-        }
         $cflags = getenv('SPC_DEFAULT_C_FLAGS') ?: getenv('CFLAGS') ?: '';
         $has_avx512 = str_contains($cflags, '-mavx512') || str_contains($cflags, '-march=x86-64-v4');
         if (!$has_avx512) {