diff --git a/src/SPC/builder/Extension.php b/src/SPC/builder/Extension.php
index 8517f1e5..331d2986 100644
--- a/src/SPC/builder/Extension.php
+++ b/src/SPC/builder/Extension.php
@@ -233,8 +233,7 @@ class Extension
         if (preg_match('/^(.*_SHARED_LIBADD\s*=\s*)(.*)$/m', $makefileContent, $matches)) {
             $prefix = $matches[1];
             $currentLibs = trim($matches[2]);
-            $lzig = ToolchainManager::getToolchainClass() === ZigToolchain::class ? '-lcompiler_rt -lunwind' : '';
-            $newLibs = clean_spaces("{$currentLibs} {$staticLibs} {$lstdcpp} {$lzig}");
+            $newLibs = clean_spaces("{$currentLibs} {$staticLibs} {$lstdcpp}");
             $deduplicatedLibs = deduplicate_flags($newLibs);
 
             FileSystem::replaceFileRegex(
diff --git a/src/SPC/builder/linux/LinuxBuilder.php b/src/SPC/builder/linux/LinuxBuilder.php
index d959aade..ffc034a7 100644
--- a/src/SPC/builder/linux/LinuxBuilder.php
+++ b/src/SPC/builder/linux/LinuxBuilder.php
@@ -65,7 +65,8 @@ class LinuxBuilder extends UnixBuilderBase
             // php 8.5 contains opcache extension by default,
             // if opcache_jit is enabled for 8.5 or opcache enabled,
             // we need to disable undefined behavior sanitizer.
-            f_putenv('SPC_COMPILER_EXTRA=-fno-sanitize=undefined');
+            $compiler_extra = getenv('SPC_COMPILER_EXTRA') ?: '';
+            f_putenv('SPC_COMPILER_EXTRA=' . trim($compiler_extra . ' -fno-sanitize=undefined'));
         }
 
         if ($this->getOption('enable-zts', false)) {
diff --git a/src/SPC/toolchain/ZigToolchain.php b/src/SPC/toolchain/ZigToolchain.php
index 1b7cc70d..6ff67769 100644
--- a/src/SPC/toolchain/ZigToolchain.php
+++ b/src/SPC/toolchain/ZigToolchain.php
@@ -64,6 +64,12 @@ 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) {