diff --git a/ShellPkg/Library/BaseSortLib/BaseSortLib.c b/ShellPkg/Library/BaseSortLib/BaseSortLib.c
index 49327153e2..ceedc884c0 100644
--- a/ShellPkg/Library/BaseSortLib/BaseSortLib.c
+++ b/ShellPkg/Library/BaseSortLib/BaseSortLib.c
@@ -177,6 +177,7 @@ PerformQuickSort (
   ASSERT and return 0.
 **/
 INTN
+EFIAPI
 DevicePathCompare (
   IN  CONST VOID             *Buffer1,
   IN  CONST VOID             *Buffer2