diff --git a/kernel/include/kernel/Thread.h b/kernel/include/kernel/Thread.h
index 9c3c9e4f..42d094aa 100644
--- a/kernel/include/kernel/Thread.h
+++ b/kernel/include/kernel/Thread.h
@@ -177,7 +177,9 @@ namespace Kernel
 		bool                       m_is_userspace         { false };
 		bool                       m_delete_process       { false };
 
+		bool                       m_has_custom_fsbase    { false };
 		vaddr_t                    m_fsbase               { 0 };
+		bool                       m_has_custom_gsbase    { false };
 		vaddr_t                    m_gsbase               { 0 };
 
 		SchedulerQueue::Node*      m_scheduler_node       { nullptr };
diff --git a/kernel/kernel/Process.cpp b/kernel/kernel/Process.cpp
index 255991f3..eb0eb4ae 100644
--- a/kernel/kernel/Process.cpp
+++ b/kernel/kernel/Process.cpp
@@ -3302,7 +3302,9 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_set_fsbase(void* addr)
 	{
-		Thread::current().set_fsbase(reinterpret_cast<vaddr_t>(addr));
+		auto& thread = Thread::current();
+		thread.m_has_custom_fsbase = true;
+		thread.set_fsbase(reinterpret_cast<vaddr_t>(addr));
 		Processor::load_fsbase();
 		return 0;
 	}
@@ -3314,7 +3316,9 @@ namespace Kernel
 
 	BAN::ErrorOr<long> Process::sys_set_gsbase(void* addr)
 	{
-		Thread::current().set_gsbase(reinterpret_cast<vaddr_t>(addr));
+		auto& thread = Thread::current();
+		thread.m_has_custom_gsbase = true;
+		thread.set_gsbase(reinterpret_cast<vaddr_t>(addr));
 		Processor::load_gsbase();
 		return 0;
 	}
diff --git a/kernel/kernel/Thread.cpp b/kernel/kernel/Thread.cpp
index 2eafc640..485cceb6 100644
--- a/kernel/kernel/Thread.cpp
+++ b/kernel/kernel/Thread.cpp
@@ -305,6 +305,14 @@ namespace Kernel
 		if (!is_userspace() || !has_process())
 			return;
 
+#if ARCH(x86_64)
+		if (m_has_custom_gsbase)
+			return;
+#elif ARCH(i686)
+		if (m_has_custom_fsbase)
+			return;
+#endif
+
 		const vaddr_t vaddr = process().shared_page_vaddr() + Processor::current_index();
 
 #if ARCH(x86_64)