diff --git a/reactos/include/ddk/wdm.h b/reactos/include/ddk/wdm.h
index d13ab0ed373..39e46812516 100644
--- a/reactos/include/ddk/wdm.h
+++ b/reactos/include/ddk/wdm.h
@@ -11528,16 +11528,10 @@ RtlCheckBit(
 #endif /* !defined(MIDL_PASS) */
 
 /* Byte Swap Functions */
-#if (defined(_M_IX86) && (_MSC_FULL_VER > 13009037 || defined(__GNUC__))) || \
-    ((defined(_M_AMD64) || defined(_M_IA64)) \
-        && (_MSC_FULL_VER > 13009175 || defined(__GNUC__)))
-
 #define RtlUshortByteSwap(_x) _byteswap_ushort((USHORT)(_x))
 #define RtlUlongByteSwap(_x) _byteswap_ulong((_x))
 #define RtlUlonglongByteSwap(_x) _byteswap_uint64((_x))
 
-#endif
-
 #if DBG
 
 #define RTL_VERIFY(exp) \
diff --git a/reactos/include/ndk/rtlfuncs.h b/reactos/include/ndk/rtlfuncs.h
index a660a9cd747..d317f0623a3 100644
--- a/reactos/include/ndk/rtlfuncs.h
+++ b/reactos/include/ndk/rtlfuncs.h
@@ -1730,46 +1730,18 @@ RtlCharToInteger(
 //
 #ifdef NTOS_MODE_USER
 
-#if (defined(_M_IX86) && (_MSC_FULL_VER > 13009037)) || \
-    ((defined(_M_AMD64) || \
-     defined(_M_IA64)) && (_MSC_FULL_VER > 13009175))
-
 unsigned short __cdecl _byteswap_ushort(unsigned short);
 unsigned long  __cdecl _byteswap_ulong (unsigned long);
 unsigned __int64 __cdecl _byteswap_uint64(unsigned __int64);
+#ifdef _MSC_VER
 #pragma intrinsic(_byteswap_ushort)
 #pragma intrinsic(_byteswap_ulong)
 #pragma intrinsic(_byteswap_uint64)
+#endif // _MSC_VER
 #define RtlUshortByteSwap(_x) _byteswap_ushort((USHORT)(_x))
 #define RtlUlongByteSwap(_x) _byteswap_ulong((_x))
 #define RtlUlonglongByteSwap(_x) _byteswap_uint64((_x))
 
-#elif defined (__GNUC__)
-
-#define RtlUshortByteSwap(_x) _byteswap_ushort((USHORT)(_x))
-#define RtlUlongByteSwap(_x) _byteswap_ulong((_x))
-#define RtlUlonglongByteSwap(_x) _byteswap_uint64((_x))
-
-#else
-
-#if (NTDDI_VERSION >= NTDDI_WIN2K)
-NTSYSAPI
-USHORT
-FASTCALL
-RtlUshortByteSwap(IN USHORT Source);
-
-NTSYSAPI
-ULONG
-FASTCALL
-RtlUlongByteSwap(IN ULONG Source);
-
-NTSYSAPI
-ULONGLONG
-FASTCALL
-RtlUlonglongByteSwap(IN ULONGLONG Source);
-#endif
-
-#endif
 #endif // NTOS_MODE_USER
 
 //
diff --git a/reactos/include/xdk/rtlfuncs.h b/reactos/include/xdk/rtlfuncs.h
index f8faa8e79dd..9bf54f06bf4 100644
--- a/reactos/include/xdk/rtlfuncs.h
+++ b/reactos/include/xdk/rtlfuncs.h
@@ -3184,16 +3184,10 @@ RtlCheckBit(
 #endif /* !defined(MIDL_PASS) */
 
 /* Byte Swap Functions */
-#if (defined(_M_IX86) && (_MSC_FULL_VER > 13009037 || defined(__GNUC__))) || \
-    ((defined(_M_AMD64) || defined(_M_IA64)) \
-        && (_MSC_FULL_VER > 13009175 || defined(__GNUC__)))
-
 #define RtlUshortByteSwap(_x) _byteswap_ushort((USHORT)(_x))
 #define RtlUlongByteSwap(_x) _byteswap_ulong((_x))
 #define RtlUlonglongByteSwap(_x) _byteswap_uint64((_x))
 
-#endif
-
 #if DBG
 
 #define RTL_VERIFY(exp) \