diff --git a/Core/HLE/HLEHelperThread.cpp b/Core/HLE/HLEHelperThread.cpp
index 97b947ceab..a55e065d42 100644
--- a/Core/HLE/HLEHelperThread.cpp
+++ b/Core/HLE/HLEHelperThread.cpp
@@ -55,11 +55,12 @@ HLEHelperThread::~HLEHelperThread() {
 
 void HLEHelperThread::AllocEntry(u32 size) {
 	entry_ = kernelMemory.Alloc(size);
+	Memory::Memset(entry_, 0, size);
 	currentMIPS->InvalidateICache(entry_, size);
 }
 
 void HLEHelperThread::Create(const char *threadName, u32 prio, int stacksize) {
-	id_ = __KernelCreateThreadInternal(threadName, __KernelGetCurThreadModuleId(), entry_, prio, stacksize, 0);
+	id_ = __KernelCreateThreadInternal(threadName, __KernelGetCurThreadModuleId(), entry_, prio, stacksize, 0x00001000);
 }
 
 void HLEHelperThread::DoState(PointerWrap &p) {
@@ -79,3 +80,7 @@ void HLEHelperThread::Start(u32 a0, u32 a1) {
 void HLEHelperThread::Terminate() {
 	__KernelStopThread(id_, SCE_KERNEL_ERROR_THREAD_TERMINATED, "helper terminated");
 }
+
+bool HLEHelperThread::Stopped() {
+	return KernelIsThreadDormant(id_);
+}
diff --git a/Core/HLE/HLEHelperThread.h b/Core/HLE/HLEHelperThread.h
index db123b81f6..7b00466fe7 100644
--- a/Core/HLE/HLEHelperThread.h
+++ b/Core/HLE/HLEHelperThread.h
@@ -31,6 +31,7 @@ public:
 
 	void Start(u32 a0, u32 a1);
 	void Terminate();
+	bool Stopped();
 
 private:
 	void AllocEntry(u32 size);
@@ -38,4 +39,4 @@ private:
 
 	SceUID id_;
 	u32 entry_;
-};
\ No newline at end of file
+};
diff --git a/Core/HLE/sceKernelThread.cpp b/Core/HLE/sceKernelThread.cpp
index a909cc3687..948bf9fb2d 100644
--- a/Core/HLE/sceKernelThread.cpp
+++ b/Core/HLE/sceKernelThread.cpp
@@ -399,8 +399,9 @@ public:
 	static int GetStaticIDType() { return SCE_KERNEL_TMID_Thread; }
 	int GetIDType() const override { return SCE_KERNEL_TMID_Thread; }
 
-	bool AllocateStack(u32 &stackSize)
-	{
+	bool AllocateStack(u32 &stackSize) {
+		_assert_msg_(SCEKERNEL, stackSize >= 0x200, "thread stack should be 256 bytes or larger");
+
 		FreeStack();
 
 		bool fromTop = (nt.attr & PSP_THREAD_ATTR_LOW_STACK) == 0;
@@ -1183,6 +1184,14 @@ const char *__KernelGetThreadName(SceUID threadID)
 	return "ERROR";
 }
 
+bool KernelIsThreadDormant(SceUID threadID) {
+	u32 error;
+	Thread *t = kernelObjects.Get<Thread>(threadID, error);
+	if (t)
+		return (t->nt.status & (THREADSTATUS_DEAD | THREADSTATUS_DORMANT)) != 0;
+	return 0;
+}
+
 u32 __KernelGetWaitValue(SceUID threadID, u32 &error)
 {
 	Thread *t = kernelObjects.Get<Thread>(threadID, error);
@@ -2352,6 +2361,13 @@ SceUID __KernelGetCurThread()
 	return currentThread;
 }
 
+int KernelCurThreadPriority() {
+	Thread *t = __GetCurrentThread();
+	if (t)
+		return t->nt.currentPriority;
+	return 0;
+}
+
 SceUID __KernelGetCurThreadModuleId()
 {
 	Thread *t = __GetCurrentThread();
diff --git a/Core/HLE/sceKernelThread.h b/Core/HLE/sceKernelThread.h
index a7a127f638..45b9387628 100644
--- a/Core/HLE/sceKernelThread.h
+++ b/Core/HLE/sceKernelThread.h
@@ -161,9 +161,11 @@ KernelObject *__KernelCallbackObject();
 
 void __KernelScheduleWakeup(int threadnumber, s64 usFromNow);
 SceUID __KernelGetCurThread();
+int KernelCurThreadPriority();
 u32 __KernelGetCurThreadStack();
 u32 __KernelGetCurThreadStackStart();
 const char *__KernelGetThreadName(SceUID threadID);
+bool KernelIsThreadDormant(SceUID threadID);
 
 void __KernelSaveContext(ThreadContext *ctx, bool vfpuEnabled);
 void __KernelLoadContext(ThreadContext *ctx, bool vfpuEnabled);
diff --git a/Core/HLE/scePsmf.cpp b/Core/HLE/scePsmf.cpp
index e05ea4b3a4..6a12e7510a 100644
--- a/Core/HLE/scePsmf.cpp
+++ b/Core/HLE/scePsmf.cpp
@@ -220,7 +220,7 @@ public:
 
 	void ScheduleFinish(u32 handle) {
 		if (!finishThread) {
-			finishThread = new HLEHelperThread("scePsmfPlayer", "scePsmfPlayer", "__PsmfPlayerFinish", playbackThreadPriority, 0x100);
+			finishThread = new HLEHelperThread("scePsmfPlayer", "scePsmfPlayer", "__PsmfPlayerFinish", playbackThreadPriority, 0x200);
 			finishThread->Start(handle, 0);
 		}
 	}