diff --git a/reactos/lib/ntdll/def/ntdll.def b/reactos/lib/ntdll/def/ntdll.def
index 7665999573e..4cf36dcbe20 100644
--- a/reactos/lib/ntdll/def/ntdll.def
+++ b/reactos/lib/ntdll/def/ntdll.def
@@ -621,6 +621,7 @@ RtlSetInformationAcl@16
 RtlSetLastWin32Error@4
 RtlSetLastWin32ErrorAndNtStatusFromNtStatus@4
 RtlSetOwnerSecurityDescriptor@12
+RtlSetProcessIsCritical@12
 RtlSetSaclSecurityDescriptor@16
 RtlSetSecurityDescriptorRMControl@8
 RtlSetSecurityObject@20
diff --git a/reactos/lib/rtl/process.c b/reactos/lib/rtl/process.c
index 17807fec5dd..88a81995ea8 100644
--- a/reactos/lib/rtl/process.c
+++ b/reactos/lib/rtl/process.c
@@ -340,4 +340,18 @@ RtlEncodePointer(IN PVOID Pointer)
   return (PVOID)((ULONG_PTR)Pointer ^ Cookie);
 }
 
+/*
+ * @unimplemented
+ */
+NTSYSAPI
+VOID
+NTAPI
+RtlSetProcessIsCritical(
+    IN   BOOLEAN   NewValue,
+    OUT  PBOOLEAN  OldValue OPTIONAL,
+    IN   BOOLEAN   IsWinlogon)
+{
+	//TODO
+}
+
 /* EOF */