diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h
index d94b8a5f93..4680e64136 100644
--- a/MdePkg/Include/Base.h
+++ b/MdePkg/Include/Base.h
@@ -621,9 +621,9 @@ typedef char* VA_LIST;
 #define VA_END(Marker)                  (Marker = (VA_LIST) 0)
 #define VA_COPY(Dest, Start)            ((void)((Dest) = (Start)))
 
-#elif defined(__GNUC__)
+#elif defined(__GNUC__) || defined(__clang__)
 
-#if defined(MDE_CPU_X64) && !defined(NO_MSABI_VA_FUNCS)
+#if defined(MDE_CPU_X64) && !defined(NO_MSABI_VA_FUNCS) && !defined(__clang__)
 //
 // X64 only. Use MS ABI version of GCC built-in macros for variable argument lists.
 //
@@ -1274,7 +1274,7 @@ typedef UINTN RETURN_STATUS;
 
   **/
   #define RETURN_ADDRESS(L)     ((L == 0) ? _ReturnAddress() : (VOID *) 0)
-#elif defined(__GNUC__)
+#elif defined (__GNUC__) || defined (__clang__)
   void * __builtin_return_address (unsigned int level);
   /**
     Get the return address of the calling function.
diff --git a/MdePkg/Include/Ia32/ProcessorBind.h b/MdePkg/Include/Ia32/ProcessorBind.h
index 497c58b33b..fa4b7e8e98 100644
--- a/MdePkg/Include/Ia32/ProcessorBind.h
+++ b/MdePkg/Include/Ia32/ProcessorBind.h
@@ -281,7 +281,7 @@ typedef INT32   INTN;
   /// Microsoft* compiler specific method for EFIAPI calling convention.
   ///
   #define EFIAPI __cdecl
-#elif defined(__GNUC__)
+#elif defined(__GNUC__) || defined(__clang__)
   ///
   /// GCC specific method for EFIAPI calling convention.
   ///
@@ -294,7 +294,7 @@ typedef INT32   INTN;
   #define EFIAPI
 #endif
 
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__clang__)
   ///
   /// For GNU assembly code, .global or .globl can declare global symbols.
   /// Define this macro to unify the usage.
diff --git a/MdePkg/Include/X64/ProcessorBind.h b/MdePkg/Include/X64/ProcessorBind.h
index 6f65acd609..387e9c5c9c 100644
--- a/MdePkg/Include/X64/ProcessorBind.h
+++ b/MdePkg/Include/X64/ProcessorBind.h
@@ -313,7 +313,7 @@ typedef INT64   INTN;
   #define EFIAPI
 #endif
 
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__clang__)
   ///
   /// For GNU assembly code, .global or .globl can declare global symbols.
   /// Define this macro to unify the usage.