diff --git a/Core/HLE/sceKernelThread.cpp b/Core/HLE/sceKernelThread.cpp
index 2e75cef841..1d5bc12cae 100644
--- a/Core/HLE/sceKernelThread.cpp
+++ b/Core/HLE/sceKernelThread.cpp
@@ -92,8 +92,8 @@ enum {
 	PSP_THREAD_ATTR_KERNEL =           0x00001000,
 	PSP_THREAD_ATTR_VFPU =             0x00004000,
 	PSP_THREAD_ATTR_SCRATCH_SRAM =     0x00008000,   // Save/restore scratch as part of context???
-	PSP_THREAD_ATTR_NO_FILLSTACK =     0x00100000,   // No filling of 0xff (only with PSP_THREAD_ATTR_LOW_STACK?)
-	PSP_THREAD_ATTR_CLEAR_STACK =      0x00200000,   // TODO: Clear thread stack when deleted
+	PSP_THREAD_ATTR_NO_FILLSTACK =     0x00100000,   // No filling of 0xff.
+	PSP_THREAD_ATTR_CLEAR_STACK =      0x00200000,   // Clear thread stack when deleted.
 	PSP_THREAD_ATTR_LOW_STACK =        0x00400000,   // Allocate stack from bottom not top.
 	PSP_THREAD_ATTR_USER =             0x80000000,
 	PSP_THREAD_ATTR_USBWLAN =          0xa0000000,
@@ -102,7 +102,7 @@ enum {
 	// TODO: Support more, not even sure what all of these mean.
 	PSP_THREAD_ATTR_USER_MASK =        0xf8f060ff,
 	PSP_THREAD_ATTR_USER_ERASE =       0x78800000,
-	PSP_THREAD_ATTR_SUPPORTED =        (PSP_THREAD_ATTR_KERNEL | PSP_THREAD_ATTR_VFPU | PSP_THREAD_ATTR_NO_FILLSTACK | PSP_THREAD_ATTR_LOW_STACK | PSP_THREAD_ATTR_USER)
+	PSP_THREAD_ATTR_SUPPORTED =        (PSP_THREAD_ATTR_KERNEL | PSP_THREAD_ATTR_VFPU | PSP_THREAD_ATTR_NO_FILLSTACK | PSP_THREAD_ATTR_CLEAR_STACK | PSP_THREAD_ATTR_LOW_STACK | PSP_THREAD_ATTR_USER)
 };
 
 struct NativeCallback
@@ -436,6 +436,11 @@ public:
 	void FreeStack() {
 		if (currentStack.start != 0) {
 			DEBUG_LOG(SCEKERNEL, "Freeing thread stack %s", nt.name);
+
+			if (nt.attr & PSP_THREAD_ATTR_CLEAR_STACK) {
+				Memory::Memset(currentStack.start, 0, currentStack.end - currentStack.start);
+			}
+
 			if (nt.attr & PSP_THREAD_ATTR_KERNEL) {
 				kernelMemory.Free(currentStack.start);
 			} else {