diff --git a/userspace/libraries/LibC/icxxabi.cpp b/userspace/libraries/LibC/icxxabi.cpp
index 4f5f2eac..785762a0 100644
--- a/userspace/libraries/LibC/icxxabi.cpp
+++ b/userspace/libraries/LibC/icxxabi.cpp
@@ -1,5 +1,7 @@
-#include <stddef.h>
 #include <limits.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
 
 struct atexit_func_entry_t
 {
@@ -8,19 +10,52 @@ struct atexit_func_entry_t
 	void* dso_handle;
 };
 
-static atexit_func_entry_t s_atexit_funcs[ATEXIT_MAX];
+static atexit_func_entry_t s_atexit_funcs_storage[ATEXIT_MAX];
+static atexit_func_entry_t* s_atexit_funcs = s_atexit_funcs_storage;
+static size_t s_atexit_funcs_capacity = ATEXIT_MAX;
 static size_t s_atexit_func_count = 0;
+static pthread_mutex_t s_atexit_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 extern "C" int __cxa_atexit(void(*func)(void*), void* arg, void* dso_handle)
 {
-	if (s_atexit_func_count >= ATEXIT_MAX)
-		return -1;
+	pthread_mutex_lock(&s_atexit_mutex);
+
+	if (s_atexit_func_count >= s_atexit_funcs_capacity)
+	{
+		const size_t new_capacity = s_atexit_funcs_capacity * 2;
+
+		void* new_funcs = nullptr;
+
+		if (s_atexit_funcs == s_atexit_funcs_storage)
+		{
+			new_funcs = malloc(new_capacity * sizeof(atexit_func_entry_t));
+			if (new_funcs == nullptr)
+				goto __cxa_atexit_error;
+			memcpy(new_funcs, s_atexit_funcs, s_atexit_func_count * sizeof(atexit_func_entry_t));
+		}
+		else
+		{
+			new_funcs = realloc(s_atexit_funcs, new_capacity * sizeof(atexit_func_entry_t));
+			if (new_funcs == nullptr)
+				goto __cxa_atexit_error;
+		}
+
+		s_atexit_funcs = reinterpret_cast<atexit_func_entry_t*>(new_funcs);
+		s_atexit_funcs_capacity = new_capacity;
+	}
+
 	s_atexit_funcs[s_atexit_func_count++] = {
 		.func = func,
 		.arg = arg,
 		.dso_handle = dso_handle,
 	};
+
+	pthread_mutex_unlock(&s_atexit_mutex);
 	return 0;
+
+__cxa_atexit_error:
+	pthread_mutex_unlock(&s_atexit_mutex);
+	return -1;
 };
 
 extern "C" void __cxa_finalize(void* dso_handle)