diff --git a/kernel/scheduler.cpp b/kernel/scheduler.cpp
index 06a4ec61..2542e94b 100644
--- a/kernel/scheduler.cpp
+++ b/kernel/scheduler.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2015, 2021-2022 Jonas 'Sortie' Termansen.
+ * Copyright (c) 2011-2015, 2021-2022, 2024 Jonas 'Sortie' Termansen.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -14,7 +14,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *
  * scheduler.cpp
- * Decides the order to execute threads in and switching between them.
+ * Decides the order to execute threads in and switches between them.
  */
 
 #include <sys/types.h>
@@ -267,6 +267,7 @@ static void SwitchRegisters(struct interrupt_context* intctx,
 
 static Thread* idle_thread;
 static Thread* first_runnable_thread;
+static Thread* first_preempted_thread;
 static Thread* true_current_thread;
 static Process* init_process;
 
@@ -323,15 +324,23 @@ static Thread* PopNextThread(bool yielded)
 			return result;
 	}
 
+	// Switch to the next runnable thread that hasn't been preempted.
 	if ( first_runnable_thread )
 	{
 		result = first_runnable_thread;
 		first_runnable_thread = first_runnable_thread->scheduler_list_next;
 	}
-	else
+	// If all threads have been preempted, allow them all to run again.
+	else if ( first_preempted_thread )
 	{
-		result = idle_thread;
+		first_runnable_thread = first_preempted_thread;
+		first_preempted_thread = NULL;
+		result = first_runnable_thread;
+		first_runnable_thread = first_runnable_thread->scheduler_list_next;
 	}
+	// Otherwise there is nothing to run.
+	else
+		result = idle_thread;
 
 	return result;
 }
@@ -359,6 +368,37 @@ static void RealSwitch(struct interrupt_context* intctx, bool yielded)
 
 void Switch(struct interrupt_context* intctx)
 {
+	Thread* thread = CurrentThread();
+	if ( thread->state == ThreadState::RUNNABLE )
+	{
+		// Remove the thread from the list of runnable threads.
+		if ( thread == first_runnable_thread )
+		{
+			first_runnable_thread = thread->scheduler_list_next;
+			if ( thread == first_runnable_thread )
+				first_runnable_thread = NULL;
+		}
+		else if ( thread == first_preempted_thread )
+		{
+			first_preempted_thread = thread->scheduler_list_next;
+			if ( thread == first_preempted_thread )
+				first_preempted_thread = NULL;
+		}
+		assert(thread->scheduler_list_prev);
+		assert(thread->scheduler_list_next);
+		thread->scheduler_list_prev->scheduler_list_next = thread->scheduler_list_next;
+		thread->scheduler_list_next->scheduler_list_prev = thread->scheduler_list_prev;
+		thread->scheduler_list_prev = NULL;
+		thread->scheduler_list_next = NULL;
+
+		// Insert the thread into the list of preempted threads.
+		if ( first_preempted_thread == NULL )
+			first_preempted_thread = thread;
+		thread->scheduler_list_prev = first_preempted_thread->scheduler_list_prev;
+		thread->scheduler_list_next = first_preempted_thread;
+		first_preempted_thread->scheduler_list_prev = thread;
+		thread->scheduler_list_prev->scheduler_list_next = thread;
+	}
 	RealSwitch(intctx, false);
 }
 
@@ -437,9 +477,17 @@ void SetThreadState(Thread* thread, ThreadState state, bool wake_only)
 	     state != ThreadState::RUNNABLE )
 	{
 		if ( thread == first_runnable_thread )
+		{
 			first_runnable_thread = thread->scheduler_list_next;
-		if ( thread == first_runnable_thread )
-			first_runnable_thread = NULL;
+			if ( thread == first_runnable_thread )
+				first_runnable_thread = NULL;
+		}
+		else if ( thread == first_preempted_thread )
+		{
+			first_preempted_thread = thread->scheduler_list_next;
+			if ( thread == first_preempted_thread )
+				first_preempted_thread = NULL;
+		}
 		assert(thread->scheduler_list_prev);
 		assert(thread->scheduler_list_next);
 		thread->scheduler_list_prev->scheduler_list_next = thread->scheduler_list_next;