diff --git a/Core/HLE/HLE.cpp b/Core/HLE/HLE.cpp
index 6fbe816b45..cdc8a8d7ba 100644
--- a/Core/HLE/HLE.cpp
+++ b/Core/HLE/HLE.cpp
@@ -162,14 +162,20 @@ void HLEShutdown() {
 	mipsCallActions.clear();
 }
 
-void RegisterModule(const char *name, int numFunctions, const HLEFunction *funcTable)
-{
+int GetNumRegisteredModules() {
+	return (int)moduleDB.size();
+}
+
+void RegisterModule(const char *name, int numFunctions, const HLEFunction *funcTable) {
 	HLEModule module = {name, numFunctions, funcTable};
 	moduleDB.push_back(module);
 }
 
-int GetModuleIndex(const char *moduleName)
-{
+const HLEModule *GetModuleByIndex(int index) {
+	return &moduleDB[index];
+}
+
+int GetModuleIndex(const char *moduleName) {
 	for (size_t i = 0; i < moduleDB.size(); i++)
 		if (strcmp(moduleName, moduleDB[i].name) == 0)
 			return (int)i;
diff --git a/Core/HLE/HLE.h b/Core/HLE/HLE.h
index ba96ef4570..12a0590351 100644
--- a/Core/HLE/HLE.h
+++ b/Core/HLE/HLE.h
@@ -44,8 +44,7 @@ enum {
 	HLE_KERNEL_SYSCALL = 1 << 11,
 };
 
-struct HLEFunction
-{
+struct HLEFunction {
 	// This is the id, or nid, of the function (which is how it's linked.)
 	// Generally, the truncated least significant 32 bits of a SHA-1 hash.
 	u32 ID;
@@ -72,8 +71,7 @@ struct HLEFunction
 	u32 stackBytesToClear;
 };
 
-struct HLEModule
-{
+struct HLEModule {
 	const char *name;
 	int numFunctions;
 	const HLEFunction *funcTable;
@@ -81,8 +79,7 @@ struct HLEModule
 
 typedef char SyscallModuleName[32];
 
-struct Syscall
-{
+struct Syscall {
 	SyscallModuleName moduleName;
 	u32 symAddr;
 	u32 nid;
@@ -102,6 +99,8 @@ int GetFuncIndex(int moduleIndex, u32 nib);
 int GetModuleIndex(const char *modulename);
 
 void RegisterModule(const char *name, int numFunctions, const HLEFunction *funcTable);
+int GetNumRegisteredModules();
+const HLEModule *GetModuleByIndex(int index);
 
 // Run the current thread's callbacks after the syscall finishes.
 void hleCheckCurrentCallbacks();
diff --git a/Core/MIPS/MIPSStackWalk.cpp b/Core/MIPS/MIPSStackWalk.cpp
index 60e38a0658..065e211e02 100644
--- a/Core/MIPS/MIPSStackWalk.cpp
+++ b/Core/MIPS/MIPSStackWalk.cpp
@@ -15,6 +15,7 @@
 // Official git repository and contact information can be found at
 // https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
 
+#include "Common/Log.h"
 #include "Core/MemMap.h"
 #include "Core/Debugger/SymbolMap.h"
 #include "Core/MIPS/MIPSCodeUtils.h"
@@ -176,6 +177,10 @@ namespace MIPSStackWalk {
 
 		u32 prevEntry = INVALIDTARGET;
 		while (pc != threadEntry) {
+			if (!Memory::IsValidAddress(current.pc)) {
+				break;
+			}
+
 			u32 possibleEntry = GuessEntry(current.pc);
 			if (DetermineFrameInfo(current, possibleEntry, threadEntry, ra)) {
 				frames.push_back(current);
diff --git a/UI/ImDebugger/ImDebugger.cpp b/UI/ImDebugger/ImDebugger.cpp
index b9a3273499..a4ab7d0a72 100644
--- a/UI/ImDebugger/ImDebugger.cpp
+++ b/UI/ImDebugger/ImDebugger.cpp
@@ -11,6 +11,7 @@
 #include "Core/MIPS/MIPSTables.h"
 #include "Core/Debugger/SymbolMap.h"
 #include "Core/MemMap.h"
+#include "Core/HLE/HLE.h"
 #include "Common/System/Request.h"
 
 // Threads window
@@ -233,6 +234,27 @@ void DrawModules(MIPSDebugInterface *debug, bool *open) {
 	ImGui::End();
 }
 
+void DrawHLEModules(ImConfig &config) {
+	if (!ImGui::Begin("HLE Modules", &config.hleModulesOpen)) {
+		ImGui::End();
+		return;
+	}
+
+	const int moduleCount = GetNumRegisteredModules();
+	for (int i = 0; i < moduleCount; i++) {
+		const HLEModule *module = GetModuleByIndex(i);
+		if (ImGui::TreeNode(module->name)) {
+			for (int j = 0; j < module->numFunctions; j++) {
+				auto &func = module->funcTable[j];
+				ImGui::Text("%s(%s)", func.name, func.argmask);
+			}
+			ImGui::TreePop();
+		}
+	}
+
+	ImGui::End();
+}
+
 void ImDebugger::Frame(MIPSDebugInterface *mipsDebug) {
 	// Snapshot the coreState to avoid inconsistency.
 	const CoreState coreState = ::coreState;
@@ -272,40 +294,42 @@ void ImDebugger::Frame(MIPSDebugInterface *mipsDebug) {
 			ImGui::EndMenu();
 		}
 		if (ImGui::BeginMenu("Window")) {
-			ImGui::Checkbox("Dear ImGUI Demo", &demoOpen_);
-			ImGui::Checkbox("CPU debugger", &disasmOpen_);
-			ImGui::Checkbox("Registers", &regsOpen_);
-			ImGui::Checkbox("Callstacks", &callstackOpen_);
-			ImGui::Checkbox("HLE Modules", &modulesOpen_);
-			ImGui::Checkbox("HLE Threads", &threadsOpen_);
+			ImGui::Checkbox("Dear ImGUI Demo", &cfg_.demoOpen);
+			ImGui::Checkbox("CPU debugger", &cfg_.disasmOpen);
+			ImGui::Checkbox("Registers", &cfg_.regsOpen);
+			ImGui::Checkbox("Callstacks", &cfg_.callstackOpen);
+			ImGui::Checkbox("HLE Modules", &cfg_.modulesOpen);
+			ImGui::Checkbox("HLE Threads", &cfg_.threadsOpen);
 			ImGui::EndMenu();
 		}
 		ImGui::EndMainMenuBar();
 	}
 
-	if (demoOpen_) {
-		ImGui::ShowDemoWindow(&demoOpen_);
+	if (cfg_.demoOpen) {
+		ImGui::ShowDemoWindow(&cfg_.demoOpen);
 	}
 
-	if (disasmOpen_) {
-		disasm_.Draw(mipsDebug, &disasmOpen_, coreState);
+	if (cfg_.disasmOpen) {
+		disasm_.Draw(mipsDebug, &cfg_.disasmOpen, coreState);
 	}
 
-	if (regsOpen_) {
-		DrawRegisterView(mipsDebug, &regsOpen_);
+	if (cfg_.regsOpen) {
+		DrawRegisterView(mipsDebug, &cfg_.regsOpen);
 	}
 
-	if (threadsOpen_) {
-		DrawThreadView(&threadsOpen_);
+	if (cfg_.threadsOpen) {
+		DrawThreadView(&cfg_.threadsOpen);
 	}
 
-	if (callstackOpen_) {
-		DrawCallStacks(mipsDebug, &callstackOpen_);
+	if (cfg_.callstackOpen) {
+		DrawCallStacks(mipsDebug, &cfg_.callstackOpen);
 	}
 
-	if (modulesOpen_) {
-		DrawModules(mipsDebug, &modulesOpen_);
+	if (cfg_.modulesOpen) {
+		DrawModules(mipsDebug, &cfg_.modulesOpen);
 	}
+
+	DrawHLEModules(cfg_);
 }
 
 void ImDisasmWindow::Draw(MIPSDebugInterface *mipsDebug, bool *open, CoreState coreState) {
diff --git a/UI/ImDebugger/ImDebugger.h b/UI/ImDebugger/ImDebugger.h
index 1eba71030c..cb2279bb93 100644
--- a/UI/ImDebugger/ImDebugger.h
+++ b/UI/ImDebugger/ImDebugger.h
@@ -48,6 +48,19 @@ public:
 	// Stub
 };
 
+struct ImConfig {
+	bool disasmOpen = true;
+	bool demoOpen  = false;
+	bool regsOpen = true;
+	bool threadsOpen = true;
+	bool callstackOpen = true;
+	bool modulesOpen = true;
+	bool hleModulesOpen = true;
+
+	// HLE explorer settings
+	// bool filterByUsed = true;
+};
+
 struct ImDebugger {
 	void Frame(MIPSDebugInterface *mipsDebug);
 
@@ -55,10 +68,5 @@ struct ImDebugger {
 	ImLuaConsole luaConsole_;
 
 	// Open variables.
-	bool disasmOpen_ = true;
-	bool demoOpen_ = false;
-	bool regsOpen_ = true;
-	bool threadsOpen_ = true;
-	bool callstackOpen_ = true;
-	bool modulesOpen_ = true;
+	ImConfig cfg_;
 };