diff --git a/src/backend_x64/callback.cpp b/src/backend_x64/callback.cpp
index 693326ff..4b2aee30 100644
--- a/src/backend_x64/callback.cpp
+++ b/src/backend_x64/callback.cpp
@@ -9,23 +9,23 @@
 
 namespace Dynarmic::BackendX64 {
 
-void SimpleCallback::EmitCall(BlockOfCode& code, std::function<void(RegList)> l) {
+void SimpleCallback::EmitCall(BlockOfCode& code, std::function<void(RegList)> l) const {
     l({code.ABI_PARAM1, code.ABI_PARAM2, code.ABI_PARAM3, code.ABI_PARAM4});
     code.CallFunction(fn);
 }
 
-void SimpleCallback::EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> l) {
+void SimpleCallback::EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> l) const {
     l(code.ABI_PARAM1, {code.ABI_PARAM2, code.ABI_PARAM3, code.ABI_PARAM4});
     code.CallFunction(fn);
 }
 
-void ArgCallback::EmitCall(BlockOfCode& code, std::function<void(RegList)> l) {
+void ArgCallback::EmitCall(BlockOfCode& code, std::function<void(RegList)> l) const {
     l({code.ABI_PARAM2, code.ABI_PARAM3, code.ABI_PARAM4});
     code.mov(code.ABI_PARAM1, arg);
     code.CallFunction(fn);
 }
 
-void ArgCallback::EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> l) {
+void ArgCallback::EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> l) const {
 #if defined(WIN32) && !defined(__MINGW64__)
     l(code.ABI_PARAM2, {code.ABI_PARAM3, code.ABI_PARAM4});
     code.mov(code.ABI_PARAM1, arg);
diff --git a/src/backend_x64/callback.h b/src/backend_x64/callback.h
index 6ce4da4a..2d474649 100644
--- a/src/backend_x64/callback.h
+++ b/src/backend_x64/callback.h
@@ -23,8 +23,8 @@ class Callback {
 public:
     virtual ~Callback() = default;
 
-    virtual void EmitCall(BlockOfCode& code, std::function<void(RegList)> fn = [](RegList){}) = 0;
-    virtual void EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> fn) = 0;
+    virtual void EmitCall(BlockOfCode& code, std::function<void(RegList)> fn = [](RegList){}) const = 0;
+    virtual void EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> fn) const = 0;
 };
 
 class SimpleCallback final : public Callback {
@@ -34,8 +34,8 @@ public:
 
     ~SimpleCallback() override = default;
 
-    void EmitCall(BlockOfCode& code, std::function<void(RegList)> fn = [](RegList){}) override;
-    void EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> fn) override;
+    void EmitCall(BlockOfCode& code, std::function<void(RegList)> fn = [](RegList){}) const override;
+    void EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> fn) const override;
 
 private:
     void (*fn)();
@@ -48,8 +48,8 @@ public:
 
     ~ArgCallback() override = default;
 
-    void EmitCall(BlockOfCode& code, std::function<void(RegList)> fn = [](RegList){}) override;
-    void EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> fn) override;
+    void EmitCall(BlockOfCode& code, std::function<void(RegList)> fn = [](RegList){}) const override;
+    void EmitCallWithReturnPointer(BlockOfCode& code, std::function<void(Xbyak::Reg64, RegList)> fn) const override;
 
 private:
     void (*fn)();