diff --git a/reactos/lib/rtl/sd.c b/reactos/lib/rtl/sd.c
index 2f9b113904c..1f3db1ea994 100644
--- a/reactos/lib/rtl/sd.c
+++ b/reactos/lib/rtl/sd.c
@@ -138,8 +138,8 @@ NTSTATUS NTAPI
 RtlCopySecurityDescriptor(IN PSECURITY_DESCRIPTOR pSourceSecurityDescriptor,
                           OUT PSECURITY_DESCRIPTOR pDestinationSecurityDescriptor)
 {
-  PSID Owner, Group;
-  PACL Dacl, Sacl;
+  PSID Owner = NULL, Group = NULL;
+  PACL Dacl = NULL, Sacl = NULL;
   BOOLEAN Defaulted, Present;
   DWORD OwnerLength, GroupLength;
   PSECURITY_DESCRIPTOR srcSD = pSourceSecurityDescriptor;