diff --git a/MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.c b/MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.c
index a5ee7d52fd..cf325fced7 100644
--- a/MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.c
+++ b/MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.c
@@ -88,7 +88,7 @@ OnigurumaMatch (
   OnigRegion      *Region;
   INT32           OnigResult;
   OnigErrorInfo   ErrorInfo;
-  CHAR8           ErrorMessage[ONIG_MAX_ERROR_MESSAGE_LEN];
+  OnigUChar       ErrorMessage[ONIG_MAX_ERROR_MESSAGE_LEN];
   UINT32          Index;
   OnigUChar       *Start;
   EFI_STATUS      Status;