diff --git a/EdkCompatibilityPkg/Foundation/Library/Pei/PeiLib/Decompress.c b/EdkCompatibilityPkg/Foundation/Library/Pei/PeiLib/Decompress.c
index efcda80334..ea12d02186 100644
--- a/EdkCompatibilityPkg/Foundation/Library/Pei/PeiLib/Decompress.c
+++ b/EdkCompatibilityPkg/Foundation/Library/Pei/PeiLib/Decompress.c
@@ -135,7 +135,9 @@ Returns:
 #define MAXMATCH  256
 #define THRESHOLD 3
 #define CODE_BIT  16
+#ifndef UINT8_MAX
 #define UINT8_MAX 0xff
+#endif
 #define BAD_TABLE - 1
 
 //