diff --git a/src/backend_x64/emit_x64_aes.cpp b/src/backend_x64/emit_x64_aes.cpp
index f1675271..669e923d 100644
--- a/src/backend_x64/emit_x64_aes.cpp
+++ b/src/backend_x64/emit_x64_aes.cpp
@@ -19,7 +19,7 @@ namespace AES = Common::Crypto::AES;
 
 using AESFn = void(AES::State&, const AES::State&);
 
-static void EmitAESFunction(std::array<Argument, 3> args, EmitContext& ctx, BlockOfCode& code,
+static void EmitAESFunction(RegAlloc::ArgumentInfo args, EmitContext& ctx, BlockOfCode& code,
                             IR::Inst* inst, AESFn fn) {
     constexpr u32 stack_space = static_cast<u32>(sizeof(AES::State)) * 2;
     const Xbyak::Xmm input = ctx.reg_alloc.UseXmm(args[0]);
diff --git a/src/backend_x64/reg_alloc.cpp b/src/backend_x64/reg_alloc.cpp
index 3e8ae2c8..78810998 100644
--- a/src/backend_x64/reg_alloc.cpp
+++ b/src/backend_x64/reg_alloc.cpp
@@ -208,8 +208,8 @@ bool Argument::IsInMemory() const {
     return HostLocIsSpill(*reg_alloc.ValueLocation(value.GetInst()));
 }
 
-std::array<Argument, 3> RegAlloc::GetArgumentInfo(IR::Inst* inst) {
-    std::array<Argument, 3> ret = { Argument{*this}, Argument{*this}, Argument{*this} };
+RegAlloc::ArgumentInfo RegAlloc::GetArgumentInfo(IR::Inst* inst) {
+    ArgumentInfo ret = { Argument{*this}, Argument{*this}, Argument{*this} };
     for (size_t i = 0; i < inst->NumArgs(); i++) {
         const IR::Value& arg = inst->GetArg(i);
         ret[i].value = arg;
diff --git a/src/backend_x64/reg_alloc.h b/src/backend_x64/reg_alloc.h
index 028e8510..ac352167 100644
--- a/src/backend_x64/reg_alloc.h
+++ b/src/backend_x64/reg_alloc.h
@@ -91,10 +91,12 @@ private:
 
 class RegAlloc final {
 public:
+    using ArgumentInfo = std::array<Argument, 3>;
+
     explicit RegAlloc(BlockOfCode& code, size_t num_spills, std::function<Xbyak::Address(HostLoc)> spill_to_addr)
         : hostloc_info(NonSpillHostLocCount + num_spills), code(code), spill_to_addr(std::move(spill_to_addr)) {}
 
-    std::array<Argument, 3> GetArgumentInfo(IR::Inst* inst);
+    ArgumentInfo GetArgumentInfo(IR::Inst* inst);
 
     Xbyak::Reg64 UseGpr(Argument& arg);
     Xbyak::Xmm UseXmm(Argument& arg);