diff --git a/CryptoPkg/Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c b/CryptoPkg/Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c
index 79bb0678e3..616ee7717e 100644
--- a/CryptoPkg/Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c
+++ b/CryptoPkg/Library/BaseCryptLib/SysCall/RuntimeMemAllocation.c
@@ -64,7 +64,7 @@ RT_MEMORY_PAGE_TABLE  *mRTPageTable = NULL;
 //
 // Event for Runtime Address Conversion.
 //
-EFI_EVENT             mVirtualAddressChangeEvent;
+STATIC EFI_EVENT      mVirtualAddressChangeEvent;
 
 
 /**