diff --git a/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/Ebc/EdkIIGlueProcessorBind.h b/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/Ebc/EdkIIGlueProcessorBind.h
index 52343e5d66..b31a81e9ae 100644
--- a/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/Ebc/EdkIIGlueProcessorBind.h
+++ b/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/Ebc/EdkIIGlueProcessorBind.h
@@ -28,13 +28,13 @@ Abstract:
 //  if the /OPT:REF linker option is used. We defined a macro as this is a 
 //  a non standard extension
 //
-#if _MSC_EXTENSIONS
+#if defined(_MSC_EXTENSIONS)
   #define GLOBAL_REMOVE_IF_UNREFERENCED __declspec(selectany)
 #else
   #define GLOBAL_REMOVE_IF_UNREFERENCED
 #endif
 
-#ifndef MDE_CPU_EBC
+#if !defined(MDE_CPU_EBC)
   #define MDE_CPU_EBC
 #endif   
 
diff --git a/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/Ipf/EdkIIGlueProcessorBind.h b/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/Ipf/EdkIIGlueProcessorBind.h
index beb31c689a..130c6b870c 100644
--- a/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/Ipf/EdkIIGlueProcessorBind.h
+++ b/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/Ipf/EdkIIGlueProcessorBind.h
@@ -28,13 +28,13 @@ Abstract:
 //  if the /OPT:REF linker option is used. We defined a macro as this is a 
 //  a non standard extension
 //
-#if _MSC_EXTENSIONS
+#if defined(_MSC_EXTENSIONS)
   #define GLOBAL_REMOVE_IF_UNREFERENCED __declspec(selectany)
 #else
   #define GLOBAL_REMOVE_IF_UNREFERENCED
 #endif
 
-#ifndef MDE_CPU_IPF
+#if !defined(MDE_CPU_IPF)
   #define MDE_CPU_IPF
 #endif
 
diff --git a/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/X64/EdkIIGlueProcessorBind.h b/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/X64/EdkIIGlueProcessorBind.h
index e362db86f5..b9b6f37347 100644
--- a/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/X64/EdkIIGlueProcessorBind.h
+++ b/EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Include/X64/EdkIIGlueProcessorBind.h
@@ -28,13 +28,13 @@ Abstract:
 //  if the /OPT:REF linker option is used. We defined a macro as this is a 
 //  a non standard extension
 //
-#if _MSC_EXTENSIONS
+#if defined(_MSC_EXTENSIONS)
   #define GLOBAL_REMOVE_IF_UNREFERENCED __declspec(selectany)
 #else
   #define GLOBAL_REMOVE_IF_UNREFERENCED
 #endif
 
-#ifndef MDE_CPU_X64
+#if !defined(MDE_CPU_X64)
   #define MDE_CPU_X64
 #endif