diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 2eda9ad3..83ae9cc9 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -165,7 +165,7 @@ jobs:
           max_attempts: 3
           retry_on: error
           command: |
-            bin/spc download --for-extensions="$(php src/globals/test-extensions.php extensions)" --for-libs="$(php src/globals/test-extensions.php libs)" --with-php=${{ matrix.php }} --ignore-cache-sources=php-src --debug
+            bin/spc download --for-extensions="$(php src/globals/test-extensions.php extensions)" --for-libs="$(php src/globals/test-extensions.php libs)" --with-php=${{ matrix.php }} --ignore-cache-sources=php-src --debug --retry=3
 
       - name: "Run Build Tests (build)"
         run: bin/spc build "$(php src/globals/test-extensions.php extensions)" --with-libs="$(php src/globals/test-extensions.php libs)" --build-cli --build-micro --build-fpm --debug
diff --git a/src/SPC/builder/extension/intl.php b/src/SPC/builder/extension/intl.php
new file mode 100644
index 00000000..8130b5d3
--- /dev/null
+++ b/src/SPC/builder/extension/intl.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SPC\builder\extension;
+
+use SPC\builder\Extension;
+use SPC\store\FileSystem;
+use SPC\util\CustomExt;
+
+#[CustomExt('intl')]
+class intl extends Extension
+{
+    public function patchBeforeBuildconf(): bool
+    {
+        // TODO: remove the following line when https://github.com/php/php-src/pull/14002 will be released
+        FileSystem::replaceFileStr(SOURCE_PATH . '/php-src/ext/intl/config.m4', 'PHP_CXX_COMPILE_STDCXX(11', 'PHP_CXX_COMPILE_STDCXX(17');
+        // Also need to use clang++ -std=c++17 to force override the default C++ standard
+        if (is_string($env = getenv('CXX')) && !str_contains($env, 'std=c++17')) {
+            f_putenv('CXX=' . $env . ' -std=c++17');
+        } else {
+            f_putenv('CXX=clang++ -std=c++17');
+        }
+        return true;
+    }
+}
diff --git a/src/SPC/builder/linux/library/icu.php b/src/SPC/builder/linux/library/icu.php
index c2d579f5..dc0939da 100644
--- a/src/SPC/builder/linux/library/icu.php
+++ b/src/SPC/builder/linux/library/icu.php
@@ -11,7 +11,7 @@ class icu extends LinuxLibraryBase
     protected function build(): void
     {
         $cppflags = 'CPPFLAGS="-DU_CHARSET_IS_UTF8=1  -DU_USING_ICU_NAMESPACE=1  -DU_STATIC_IMPLEMENTATION=1"';
-        $cxxflags = 'CXXFLAGS="-std=c++11"';
+        $cxxflags = 'CXXFLAGS="-std=c++17"';
         $ldflags = 'LDFLAGS="-static"';
         shell()->cd($this->source_dir . '/source')
             ->exec(
diff --git a/src/globals/test-extensions.php b/src/globals/test-extensions.php
index c7127f0d..3aae34b1 100644
--- a/src/globals/test-extensions.php
+++ b/src/globals/test-extensions.php
@@ -13,7 +13,7 @@ declare(strict_types=1);
 
 // If you want to test your added extensions and libs, add below (comma separated, example `bcmath,openssl`).
 $extensions = match (PHP_OS_FAMILY) {
-    'Linux', 'Darwin' => 'uuid',
+    'Linux', 'Darwin' => 'intl,posix',
     'Windows' => 'mbstring,pdo_sqlite,mbregex',
 };