diff --git a/Source/Core/Core/HLE/HLE_VarArgs.cpp b/Source/Core/Core/HLE/HLE_VarArgs.cpp
index b16d1dfd32d..148215d4172 100644
--- a/Source/Core/Core/HLE/HLE_VarArgs.cpp
+++ b/Source/Core/Core/HLE/HLE_VarArgs.cpp
@@ -6,6 +6,7 @@
 #include "Common/Logging/Log.h"
 
 #include "Core/Core.h"
+#include "Core/PowerPC/PowerPC.h"
 #include "Core/System.h"
 
 HLE::SystemVABI::VAList::~VAList() = default;
diff --git a/Source/Core/Core/HLE/HLE_VarArgs.h b/Source/Core/Core/HLE/HLE_VarArgs.h
index c1a9f0a7707..e1f7c55090c 100644
--- a/Source/Core/Core/HLE/HLE_VarArgs.h
+++ b/Source/Core/Core/HLE/HLE_VarArgs.h
@@ -9,7 +9,6 @@
 #include "Common/CommonTypes.h"
 
 #include "Core/PowerPC/MMU.h"
-#include "Core/PowerPC/PowerPC.h"
 
 namespace Core
 {
@@ -19,15 +18,14 @@ class System;
 
 namespace HLE::SystemVABI
 {
-// SFINAE
 template <typename T>
-constexpr bool IS_ARG_POINTER = std::is_union<T>() || std::is_class<T>();
+concept ArgPointer = std::is_union_v<T> || std::is_class_v<T>;
 template <typename T>
-constexpr bool IS_WORD = std::is_pointer<T>() || (std::is_integral<T>() && sizeof(T) <= 4);
+concept ArgWord = std::is_pointer_v<T> || (std::is_integral_v<T> && sizeof(T) <= 4);
 template <typename T>
-constexpr bool IS_DOUBLE_WORD = std::is_integral<T>() && sizeof(T) == 8;
+concept ArgDoubleWord = std::is_integral_v<T> && sizeof(T) == 8;
 template <typename T>
-constexpr bool IS_ARG_REAL = std::is_floating_point<T>();
+concept ArgReal = std::is_floating_point_v<T>;
 
 // See System V ABI (SVR4) for more details
 //  -> 3-18 Parameter Passing
@@ -47,7 +45,7 @@ public:
   virtual ~VAList();
 
   // 0 - arg_ARGPOINTER
-  template <typename T, typename std::enable_if_t<IS_ARG_POINTER<T>>* = nullptr>
+  template <ArgPointer T>
   T GetArg()
   {
     T obj;
@@ -62,7 +60,7 @@ public:
   }
 
   // 1 - arg_WORD
-  template <typename T, typename std::enable_if_t<IS_WORD<T>>* = nullptr>
+  template <ArgWord T>
   T GetArg()
   {
     static_assert(!std::is_pointer<T>(), "VAList doesn't support pointers");
@@ -84,7 +82,7 @@ public:
   }
 
   // 2 - arg_DOUBLEWORD
-  template <typename T, typename std::enable_if_t<IS_DOUBLE_WORD<T>>* = nullptr>
+  template <ArgDoubleWord T>
   T GetArg()
   {
     u64 value;
@@ -107,7 +105,7 @@ public:
   }
 
   // 3 - arg_ARGREAL
-  template <typename T, typename std::enable_if_t<IS_ARG_REAL<T>>* = nullptr>
+  template <ArgReal T>
   T GetArg()
   {
     double value;