diff --git a/src/SPC/builder/Extension.php b/src/SPC/builder/Extension.php
index 3f8d54b8..410f04d8 100644
--- a/src/SPC/builder/Extension.php
+++ b/src/SPC/builder/Extension.php
@@ -222,11 +222,23 @@ class Extension
     {
         $config = (new SPCConfigUtil($this->builder))->config([$this->getName()], array_map(fn ($l) => $l->getName(), $this->builder->getLibs()));
         [$staticLibs, $sharedLibs] = $this->splitLibsIntoStaticAndShared($config['libs']);
-        FileSystem::replaceFileRegex(
-            $this->source_dir . '/Makefile',
-            '/^(.*_SHARED_LIBADD\s*=.*)$/m',
-            clean_spaces("$1 {$staticLibs} {$sharedLibs}")
-        );
+        $lstdcpp = str_contains($sharedLibs, '-lstdc++') ? '-lstdc++' : '';
+
+        $makefileContent = file_get_contents($this->source_dir . '/Makefile');
+
+        if (preg_match('/^(.*_SHARED_LIBADD\s*=\s*)(.*)$/m', $makefileContent, $matches)) {
+            $prefix = $matches[1];
+            $currentLibs = trim($matches[2]);
+            $newLibs = trim("{$currentLibs} {$staticLibs} {$lstdcpp}");
+            $deduplicatedLibs = deduplicate_flags($newLibs);
+
+            FileSystem::replaceFileRegex(
+                $this->source_dir . '/Makefile',
+                '/^(.*_SHARED_LIBADD\s*=.*)$/m',
+                $prefix . $deduplicatedLibs
+            );
+        }
+
         if ($objs = getenv('SPC_EXTRA_RUNTIME_OBJECTS')) {
             FileSystem::replaceFileRegex(
                 $this->source_dir . '/Makefile',
diff --git a/src/globals/functions.php b/src/globals/functions.php
index 71127960..c8c40b68 100644
--- a/src/globals/functions.php
+++ b/src/globals/functions.php
@@ -245,6 +245,16 @@ function clean_spaces(string $string): string
     return trim(preg_replace('/\s+/', ' ', $string));
 }
 
+function deduplicate_flags(string $flags): string
+{
+    $tokens = preg_split('/\s+/', trim($flags));
+
+    // Reverse, unique, reverse back - keeps last occurrence of duplicates
+    $deduplicated = array_reverse(array_unique(array_reverse($tokens)));
+
+    return implode(' ', $deduplicated);
+}
+
 /**
  * Register a callback function to handle keyboard interrupts (Ctrl+C).
  *