diff --git a/game/overlord/jak2/streamlist.cpp b/game/overlord/jak2/streamlist.cpp
index f6dd7614d8..e74cba7fe9 100644
--- a/game/overlord/jak2/streamlist.cpp
+++ b/game/overlord/jak2/streamlist.cpp
@@ -407,15 +407,20 @@ u32 StreamListThread() {
       }
       uVar9 = uVar9 + 1;
     } while (uVar9 < 4);
+
     SignalSema(EEStreamsList.sema);
     RequestedStreamsList.unk2_init0 = 1;
     SignalSema(RequestedStreamsList.sema);
+
     WaitSema(EEPlayList.sema);
     CheckPlayList(&EEPlayList);
     SignalSema(EEPlayList.sema);
-    WaitSema(LfoList.sema);
-    CheckLfoList(&LfoList);
-    SignalSema(LfoList.sema);
+
+    // FIXME LfoList hasn't been initialised because of unimplemented
+    // streamlfo functions.
+    // WaitSema(LfoList.sema);
+    // CheckLfoList(&LfoList);
+    // SignalSema(LfoList.sema);
   } while (true);
   return 0;
 }
diff --git a/game/system/IOP_Kernel.cpp b/game/system/IOP_Kernel.cpp
index 56b8d663ff..149c1f4d7c 100644
--- a/game/system/IOP_Kernel.cpp
+++ b/game/system/IOP_Kernel.cpp
@@ -101,7 +101,14 @@ void IOP_Kernel::DelayThread(u32 usec) {
 void IOP_Kernel::SleepThread() {
   ASSERT(_currentThread);
 
-  _currentThread->state = IopThread::State::Suspend;
+  if (_currentThread->wakeupCount > 0) {
+    _currentThread->wakeupCount--;
+    return;
+  }
+
+  _currentThread->state = IopThread::State::Wait;
+  _currentThread->waitType = IopThread::Wait::Sleep;
+
   leaveThread();
 }
 
@@ -116,6 +123,13 @@ void IOP_Kernel::YieldThread() {
  */
 void IOP_Kernel::WakeupThread(s32 id) {
   ASSERT(id > 0);
+
+  auto& thread = threads.at(id);
+  if (thread.state != IopThread::State::Wait || thread.waitType != IopThread::Wait::Sleep) {
+    thread.wakeupCount++;
+    return;
+  }
+
   threads.at(id).state = IopThread::State::Ready;
 }
 
diff --git a/game/system/IOP_Kernel.h b/game/system/IOP_Kernel.h
index 3409d639a9..065c7caa53 100644
--- a/game/system/IOP_Kernel.h
+++ b/game/system/IOP_Kernel.h
@@ -53,7 +53,7 @@ struct IopThread {
     Dormant,
   };
 
-  enum class Wait { None, Semaphore, Delay, Messagebox, EventFlag };
+  enum class Wait { None, Sleep, Semaphore, Delay, Messagebox, EventFlag };
 
   IopThread(std::string n, void (*f)(), s32 ID, u32 pri)
       : name(std::move(n)), function(f), priority(pri), thID(ID) {
@@ -71,6 +71,7 @@ struct IopThread {
   time_stamp resumeTime = {};
   u32 priority = 0;
   s32 thID = -1;
+  s32 wakeupCount = 0;
 };
 
 struct Semaphore {