diff --git a/Core/Debugger/DebugInterface.h b/Core/Debugger/DebugInterface.h
index 11559e20b7..a209c8fdeb 100644
--- a/Core/Debugger/DebugInterface.h
+++ b/Core/Debugger/DebugInterface.h
@@ -26,21 +26,19 @@ struct MemMap;
 
 class DebugInterface {
 public:
-	virtual u32 GetHi() = 0;
-	virtual u32 GetLo() = 0;
-	virtual u32 GetLLBit() = 0;
-	virtual u32 GetFPCond() = 0;
+	virtual u32 GetPC() const = 0;
+	virtual u32 GetRA() const = 0;
+	virtual u32 GetHi() const = 0;
+	virtual u32 GetLo() const = 0;
+	virtual u32 GetLLBit() const = 0;
+	virtual u32 GetFPCond() const = 0;
+	virtual u32 GetGPR32Value(int reg) const = 0;
 
+	virtual void SetPC(u32 _pc) = 0;
 	virtual void SetHi(u32 val) = 0;
 	virtual void SetLo(u32 val) = 0;
-	virtual u32 GetGPR32Value(int reg) = 0;
 
-	virtual u32 GetPC() = 0;
-	virtual void SetPC(u32 _pc) = 0;
-	virtual u32 GetRA() = 0;
-
-	// More stuff for debugger
-	virtual u32 GetRegValue(int cat, int index) = 0;
+	virtual u32 GetRegValue(int cat, int index) const = 0;
+	virtual void PrintRegValue(int cat, int index, char *out, size_t outSize) const = 0;
 	virtual void SetRegValue(int cat, int index, u32 value) {}
-	virtual void PrintRegValue(int cat, int index, char *out, size_t outSize) = 0;
 };
diff --git a/Core/HLE/KernelThreadDebugInterface.h b/Core/HLE/KernelThreadDebugInterface.h
index dbab6d57e1..5e8cee5b22 100644
--- a/Core/HLE/KernelThreadDebugInterface.h
+++ b/Core/HLE/KernelThreadDebugInterface.h
@@ -23,17 +23,20 @@
 
 class KernelThreadDebugInterface : public DebugInterface {
 public:
-	KernelThreadDebugInterface(PSPThreadContext &t) : ctx(t) {
-	}
+	KernelThreadDebugInterface(PSPThreadContext &t) : ctx(t) {}
 
-	u32 GetGPR32Value(int reg) override { return ctx.r[reg]; }
-	u32 GetPC() override { return ctx.pc; }
-	u32 GetRA() override { return ctx.r[MIPS_REG_RA]; }
-	u32 GetLLBit() override { return 0; }
-	u32 GetFPCond() override { return ctx.fpcond; }
+	u32 GetGPR32Value(int reg) const override { return ctx.r[reg]; }
+	u32 GetHi() const override { return ctx.hi; }
+	u32 GetLo() const override { return ctx.lo; }
+	u32 GetPC() const override { return ctx.pc; }
+	u32 GetRA() const override { return ctx.r[MIPS_REG_RA]; }
+	u32 GetLLBit() const override { return 0; }
+	u32 GetFPCond() const override { return ctx.fpcond; }
 	void SetPC(u32 _pc) override { ctx.pc = _pc; }
+	void SetHi(u32 val) override { ctx.hi = val; }
+	void SetLo(u32 val) override { ctx.lo = val; }
 
-	void PrintRegValue(int cat, int index, char *out, size_t outSize) override {
+	void PrintRegValue(int cat, int index, char *out, size_t outSize) const override {
 		switch (cat) {
 		case 0: snprintf(out, outSize, "%08X", ctx.r[index]); break;
 		case 1: snprintf(out, outSize, "%f", ctx.f[index]); break;
@@ -41,23 +44,7 @@ public:
 		}
 	}
 
-	u32 GetHi() override {
-		return ctx.hi;
-	}
-
-	u32 GetLo() override {
-		return ctx.lo;
-	}
-
-	void SetHi(u32 val) override {
-		ctx.hi = val;
-	}
-
-	void SetLo(u32 val) override {
-		ctx.lo = val;
-	}
-
-	u32 GetRegValue(int cat, int index) override {
+	u32 GetRegValue(int cat, int index) const override {
 		switch (cat) {
 		case 0: return ctx.r[index];
 		case 1: return ctx.fi[index];
diff --git a/Core/MIPS/MIPSDebugInterface.cpp b/Core/MIPS/MIPSDebugInterface.cpp
index 650096975e..129b4cabfb 100644
--- a/Core/MIPS/MIPSDebugInterface.cpp
+++ b/Core/MIPS/MIPSDebugInterface.cpp
@@ -54,7 +54,7 @@ enum ReferenceIndexType {
 
 class MipsExpressionFunctions : public IExpressionFunctions {
 public:
-	MipsExpressionFunctions(DebugInterface *_cpu): cpu(_cpu) {}
+	MipsExpressionFunctions(const DebugInterface *_cpu): cpu(_cpu) {}
 
 	bool parseReference(char* str, uint32_t& referenceIndex) override
 	{
@@ -199,7 +199,7 @@ public:
 	}
 
 private:
-	DebugInterface *cpu;
+	const DebugInterface *cpu;
 };
 
 unsigned int MIPSDebugInterface::readMemory(unsigned int address) {
@@ -282,12 +282,12 @@ std::string MIPSDebugInterface::GetRegName(int cat, int index) {
 	return "???";
 }
 
-bool initExpression(DebugInterface *debug, const char* exp, PostfixExpression& dest) {
+bool initExpression(const DebugInterface *debug, const char* exp, PostfixExpression& dest) {
 	MipsExpressionFunctions funcs(debug);
 	return initPostfixExpression(exp, &funcs, dest);
 }
 
-bool parseExpression(DebugInterface *debug, PostfixExpression& exp, u32& dest) {
+bool parseExpression(const DebugInterface *debug, PostfixExpression& exp, u32& dest) {
 	MipsExpressionFunctions funcs(debug);
 	return parsePostfixExpression(exp, &funcs, dest);
 }
diff --git a/Core/MIPS/MIPSDebugInterface.h b/Core/MIPS/MIPSDebugInterface.h
index d6dc40963f..f71687316b 100644
--- a/Core/MIPS/MIPSDebugInterface.h
+++ b/Core/MIPS/MIPSDebugInterface.h
@@ -39,13 +39,13 @@ public:
 	int getColor(unsigned int address, bool darkMode) const;
 	std::string getDescription(unsigned int address);
 
-	u32 GetGPR32Value(int reg) override { return cpu->r[reg]; }
-	float GetFPR32Value(int reg) { return cpu->f[reg]; }
+	u32 GetGPR32Value(int reg) const override { return cpu->r[reg]; }
+	float GetFPR32Value(int reg) const { return cpu->f[reg]; }
 	void SetGPR32Value(int reg, u32 value) { cpu->r[reg] = value; }
 
-	u32 GetPC() override { return cpu->pc; }
-	u32 GetRA() override { return cpu->r[MIPS_REG_RA]; }
-	u32 GetFPCond() override { return cpu->fpcond; }
+	u32 GetPC() const override { return cpu->pc; }
+	u32 GetRA() const override { return cpu->r[MIPS_REG_RA]; }
+	u32 GetFPCond() const override { return cpu->fpcond; }
 	void SetPC(u32 _pc) override { cpu->pc = _pc; }
 
 	static const char *GetCategoryName(int cat) {
@@ -59,7 +59,7 @@ public:
 	}
 	static std::string GetRegName(int cat, int index);
 
-	void PrintRegValue(int cat, int index, char *out, size_t outSize) override {
+	void PrintRegValue(int cat, int index, char *out, size_t outSize) const override {
 		switch (cat) {
 		case 0: snprintf(out, outSize, "%08X", cpu->r[index]); break;
 		case 1: snprintf(out, outSize, "%f", cpu->f[index]); break;
@@ -67,15 +67,15 @@ public:
 		}
 	}
 
-	u32 GetHi() override {
+	u32 GetHi() const override {
 		return cpu->hi;
 	}
 
-	u32 GetLLBit() override {
+	u32 GetLLBit() const override {
 		return cpu->llBit;
 	}
 
-	u32 GetLo() override {
+	u32 GetLo() const override {
 		return cpu->lo;
 	}
 	
@@ -87,7 +87,7 @@ public:
 		cpu->lo = val;
 	}
 
-	u32 GetRegValue(int cat, int index) override {
+	u32 GetRegValue(int cat, int index) const override {
 		switch (cat) {
 		case 0:
 			return cpu->r[index];
@@ -124,6 +124,6 @@ public:
 	}
 };
 
-bool initExpression(DebugInterface *debug, const char* exp, PostfixExpression& dest);
-bool parseExpression(DebugInterface *debug, PostfixExpression& exp, u32& dest);
+bool initExpression(const DebugInterface *debug, const char* exp, PostfixExpression& dest);
+bool parseExpression(const DebugInterface *debug, PostfixExpression& exp, u32& dest);
 void DisAsm(u32 pc, char *out, size_t outSize);