diff --git a/MdePkg/Include/x64/ProcessorBind.h b/MdePkg/Include/x64/ProcessorBind.h
index 4332b89fff..0d31352e39 100644
--- a/MdePkg/Include/x64/ProcessorBind.h
+++ b/MdePkg/Include/x64/ProcessorBind.h
@@ -70,7 +70,7 @@
 #endif
 
 
-#if (__STDC_VERSION__ < 199901L)
+#if !defined(__GNUC__) && (__STDC_VERSION__ < 199901L)
   //
   // No ANSI C 2000 stdint.h integer width declarations, so define equivalents
   //
diff --git a/Tools/CCode/Source/Include/X64/ProcessorBind.h b/Tools/CCode/Source/Include/X64/ProcessorBind.h
index f865ce8790..8cbf4915f3 100644
--- a/Tools/CCode/Source/Include/X64/ProcessorBind.h
+++ b/Tools/CCode/Source/Include/X64/ProcessorBind.h
@@ -61,7 +61,7 @@
 #endif
 
 
-#if (__STDC_VERSION__ < 199901L)
+#if !defined(__GNUC__) && (__STDC_VERSION__ < 199901L)
   //
   // No ANSI C 2000 stdint.h integer width declarations, so define equivalents
   //