diff --git a/ntoskrnl/include/internal/ob.h b/ntoskrnl/include/internal/ob.h
index 4aad5a5e253..9e4497bbff5 100644
--- a/ntoskrnl/include/internal/ob.h
+++ b/ntoskrnl/include/internal/ob.h
@@ -205,7 +205,7 @@ ObpLookupEntryDirectory(
     IN POBJECT_DIRECTORY Directory,
     IN PUNICODE_STRING Name,
     IN ULONG Attributes,
-    IN UCHAR SearchShadow,
+    IN BOOLEAN SearchShadow,
     IN POBP_LOOKUP_CONTEXT Context
 );
 
diff --git a/ntoskrnl/ob/obdir.c b/ntoskrnl/ob/obdir.c
index 3f3bc492c11..f566c995ee4 100644
--- a/ntoskrnl/ob/obdir.c
+++ b/ntoskrnl/ob/obdir.c
@@ -158,7 +158,7 @@ NTAPI
 ObpLookupEntryDirectory(IN POBJECT_DIRECTORY Directory,
                         IN PUNICODE_STRING Name,
                         IN ULONG Attributes,
-                        IN UCHAR SearchShadow,
+                        IN BOOLEAN SearchShadow,
                         IN POBP_LOOKUP_CONTEXT Context)
 {
     BOOLEAN CaseInsensitive = FALSE;