diff --git a/Core/HLE/sceKernelHeap.cpp b/Core/HLE/sceKernelHeap.cpp
index 44e6e92961..54c85ce41c 100644
--- a/Core/HLE/sceKernelHeap.cpp
+++ b/Core/HLE/sceKernelHeap.cpp
@@ -102,7 +102,10 @@ static int sceKernelAllocHeapMemory(int heapId, int size) {
 		return hleLogError(Log::sceKernel, 0, "invalid heapId");
 	}
 
-	// There's 8 bytes at the end of every block, reserved.
+	// There's 8 bytes at the end of every block, reserved. Don't let that wrap (sysmem/kernel/heap).
+	if ((u32)size > 0xFFFFFF00) {
+		return hleLogError(Log::sceKernel, 0, "invalid size %08x", size);
+	}
 	u32 memSize = KERNEL_HEAP_BLOCK_HEADER_SIZE + size;
 	u32 addr = heap->alloc.Alloc(memSize, true);
 	if (addr == (u32)-1) {
diff --git a/Core/HLE/sceKernelModule.cpp b/Core/HLE/sceKernelModule.cpp
index 54cb6bc162..54131b836e 100644
--- a/Core/HLE/sceKernelModule.cpp
+++ b/Core/HLE/sceKernelModule.cpp
@@ -3838,8 +3838,12 @@ static u32 sceKernelQueryModuleInfo(u32 uid, u32 infoAddr)
 
 static u32 sceKernelGetModuleIdList(u32 resultBuffer, u32 resultBufferSize, u32 idCountAddr)
 {
-	ERROR_LOG(Log::sceModule, "UNTESTED sceKernelGetModuleIdList(%08x, %i, %08x)", resultBuffer, resultBufferSize, idCountAddr);
-	
+	// pspautotests modules/idlist: the size is in bytes, a partial entry at the end still gets
+	// written, and the count covers every module whether it fit or not.
+	if (resultBuffer == 0 || (int)resultBufferSize < 0) {
+		return hleLogError(Log::sceModule, SCE_KERNEL_ERROR_ILLEGAL_ADDR, "bad buffer");
+	}
+
 	int idCount = 0;
 	u32 resultBufferOffset = 0;
 
@@ -3850,8 +3854,7 @@ static u32 sceKernelGetModuleIdList(u32 resultBuffer, u32 resultBufferSize, u32
 			continue;
 		}
 		if (!module->isFake || liedAboutThisModule(module)) {
-			// Only whole entries.
-			if (resultBufferOffset + 4 <= resultBufferSize) {
+			if (resultBufferOffset < resultBufferSize) {
 				Memory::WriteOrException_U32(module->GetUID(), resultBuffer + resultBufferOffset);
 				resultBufferOffset += 4;
 			}
@@ -3860,8 +3863,7 @@ static u32 sceKernelGetModuleIdList(u32 resultBuffer, u32 resultBufferSize, u32
 	}
 
 	Memory::WriteOrException_U32(idCount, idCountAddr);
-	
-	return hleNoLog(0);
+	return hleLogDebug(Log::sceModule, 0);
 }
 
 bool DescribeModuleAddress(u32 address, char *buffer, size_t bufferSize) {
diff --git a/pspautotests b/pspautotests
index e26ed03caa..88e64dd037 160000
--- a/pspautotests
+++ b/pspautotests
@@ -1 +1 @@
-Subproject commit e26ed03caaa02873159a636b9f35ba81fe08ccd3
+Subproject commit 88e64dd03767cd69e32e2197afb84f38cf7aba20
diff --git a/test.py b/test.py
index dcf8183209..8ec831539f 100755
--- a/test.py
+++ b/test.py
@@ -347,6 +347,7 @@ tests_good = [
   "misc/deadbeef",
   "modules/cutrel/cutrel",
   "modules/cutrel/kernel/cutrel",
+  "modules/idlist/idlist",
   "modules/loadrace/loadrace",
   "modules/startoptions/startoptions",
   "modules/unresolved/unresolved",