diff --git a/Core/HLE/sceKernel.cpp b/Core/HLE/sceKernel.cpp
index 6038c70725..3a003f6949 100644
--- a/Core/HLE/sceKernel.cpp
+++ b/Core/HLE/sceKernel.cpp
@@ -717,7 +717,7 @@ const HLEFunction ThreadManForUser[] =
 	{0x94aa61ee,sceKernelGetThreadCurrentPriority,"sceKernelGetThreadCurrentPriority"},
 	{0x293b45b8,WrapI_V<sceKernelGetThreadId>,"sceKernelGetThreadId"},
 	{0x3B183E26,WrapI_I<sceKernelGetThreadExitStatus>,"sceKernelGetThreadExitStatus"},
-	{0x52089CA1,sceKernelGetThreadStackFreeSize,"sceKernelGetThreadStackFreeSize"},
+	{0x52089CA1,WrapI_I<sceKernelGetThreadStackFreeSize>,      "sceKernelGetThreadStackFreeSize"},
 	{0xFFC36A14,WrapU_UU<sceKernelReferThreadRunStatus>,"sceKernelReferThreadRunStatus"},
 	{0x17c1684e,WrapU_UU<sceKernelReferThreadStatus>,"sceKernelReferThreadStatus"},
 	{0x2C34E053,WrapI_I<sceKernelReleaseWaitThread>,"sceKernelReleaseWaitThread"},
diff --git a/Core/HLE/sceKernel.h b/Core/HLE/sceKernel.h
index 846c398a43..80aedfde1e 100644
--- a/Core/HLE/sceKernel.h
+++ b/Core/HLE/sceKernel.h
@@ -389,7 +389,7 @@ int sceKernelDcacheWritebackAll();
 int sceKernelDcacheWritebackRange(u32 addr, int size);
 int sceKernelDcacheWritebackInvalidateRange(u32 addr, int size);
 int sceKernelDcacheWritebackInvalidateAll();
-void sceKernelGetThreadStackFreeSize();
+int sceKernelGetThreadStackFreeSize(SceUID threadID);
 u32 sceKernelIcacheInvalidateAll();
 u32 sceKernelIcacheClearAll();
 int sceKernelIcacheInvalidateRange(u32 addr, int size);
diff --git a/Core/HLE/sceKernelThread.cpp b/Core/HLE/sceKernelThread.cpp
index 2e617e3824..06968f73fa 100644
--- a/Core/HLE/sceKernelThread.cpp
+++ b/Core/HLE/sceKernelThread.cpp
@@ -1852,7 +1852,7 @@ int sceKernelCheckThreadStack()
 	Thread *t = kernelObjects.Get<Thread>(__KernelGetCurThread(), error);
 	if (t) {
 		u32 diff = labs((long)((s64)currentMIPS->r[MIPS_REG_SP] - (s64)t->currentStack.start));
-		WARN_LOG(SCEKERNEL, "%i=sceKernelCheckThreadStack()", diff);
+		DEBUG_LOG(SCEKERNEL, "%i=sceKernelCheckThreadStack()", diff);
 		return diff;
 	} else {
 		ERROR_LOG_REPORT(SCEKERNEL, "sceKernelCheckThreadStack() - not on thread");
@@ -2148,37 +2148,32 @@ int sceKernelStartThread(SceUID threadToStartID, int argSize, u32 argBlockPtr)
 	return 0;
 }
 
-void sceKernelGetThreadStackFreeSize()
+int sceKernelGetThreadStackFreeSize(SceUID threadID)
 {
-	SceUID threadID = PARAM(0);
-	Thread *thread;
-
-	INFO_LOG(SCEKERNEL,"sceKernelGetThreadStackFreeSize(%i)", threadID);
+	DEBUG_LOG(SCEKERNEL, "sceKernelGetThreadStackFreeSize(%i)", threadID);
 
 	if (threadID == 0)
-		thread = __GetCurrentThread();
-	else
+		threadID = currentThread;
+
+	u32 error;
+	Thread *thread = kernelObjects.Get<Thread>(threadID, error);
+	if (thread == 0)
 	{
-		u32 error;
-		thread = kernelObjects.Get<Thread>(threadID, error);
-		if (thread == 0)
-		{
-			ERROR_LOG(SCEKERNEL,"sceKernelGetThreadStackFreeSize: invalid thread id %i", threadID);
-			RETURN(error);
-			return;
-		}
+		ERROR_LOG(SCEKERNEL, "sceKernelGetThreadStackFreeSize: invalid thread id %i", threadID);
+		return error;
 	}
 
-	// Scan the stack for 0xFF
+	// Scan the stack for 0xFF, starting after 0x10 (the thread id is written there.)
+	// Obviously this doesn't work great if PSP_THREAD_ATTR_NO_FILLSTACK is used.
 	int sz = 0;
-	for (u32 addr = thread->currentStack.start; addr < thread->currentStack.start + thread->nt.stackSize; addr++)
+	for (u32 offset = 0x10; offset < thread->nt.stackSize; ++offset)
 	{
-		if (Memory::Read_U8(addr) != 0xFF)
+		if (Memory::Read_U8(thread->currentStack.start + offset) != 0xFF)
 			break;
 		sz++;
 	}
 
-	RETURN(sz & ~3);
+	return sz & ~3;
 }
 
 void __KernelReturnFromThread()
diff --git a/Core/HLE/scePower.cpp b/Core/HLE/scePower.cpp
index d16d354633..0cc8426f10 100644
--- a/Core/HLE/scePower.cpp
+++ b/Core/HLE/scePower.cpp
@@ -319,7 +319,7 @@ int sceKernelVolatileMemLock(int type, u32 paddr, u32 psize) {
 
 	case SCE_KERNEL_ERROR_ILLEGAL_CONTEXT:
 		{
-			WARN_LOG(HLE, "sceKernelVolatileMemLock(%i, %08x, %08x): dispatch disabled", type, paddr, psize);
+			WARN_LOG(HLE, "sceKernelVolatileMemLock(%i, %08x, %08x): in interrupt", type, paddr, psize);
 			Memory::Write_U32(0x08400000, paddr);
 			Memory::Write_U32(0x00400000, psize);
 		}