diff --git a/reactos/lib/advapi32/advapi32.def b/reactos/lib/advapi32/advapi32.def
index d28382f5629..d9a1b44ef24 100644
--- a/reactos/lib/advapi32/advapi32.def
+++ b/reactos/lib/advapi32/advapi32.def
@@ -47,8 +47,8 @@ BuildImpersonateExplicitAccessWithNameA@24
 BuildImpersonateExplicitAccessWithNameW@24
 BuildImpersonateTrusteeA@8
 BuildImpersonateTrusteeW@8
-;BuildSecurityDescriptorA@36
-;BuildSecurityDescriptorW@36
+BuildSecurityDescriptorA@36
+BuildSecurityDescriptorW@36
 BuildTrusteeWithNameA@8
 BuildTrusteeWithNameW@8
 BuildTrusteeWithObjectsAndNameA@24
@@ -325,7 +325,7 @@ IsTokenRestricted@4
 IsValidAcl@4
 IsValidSecurityDescriptor@4
 IsValidSid@4
-;IsWellKnownSid
+IsWellKnownSid@8
 LockServiceDatabase@4
 LogonUserA@24
 ;LogonUserExA
diff --git a/reactos/lib/advapi32/sec/sec.c b/reactos/lib/advapi32/sec/sec.c
index a01087b36a9..ec21752f688 100644
--- a/reactos/lib/advapi32/sec/sec.c
+++ b/reactos/lib/advapi32/sec/sec.c
@@ -457,4 +457,45 @@ ConvertToAutoInheritPrivateObjectSecurity(IN PSECURITY_DESCRIPTOR ParentDescript
     return FALSE;
 }
 
+
+/*
+ * @unimplemented
+ */
+DWORD
+STDCALL
+BuildSecurityDescriptorW(IN PTRUSTEE_W pOwner  OPTIONAL,
+                         IN PTRUSTEE_W pGroup  OPTIONAL,
+                         IN ULONG cCountOfAccessEntries,
+                         IN PEXPLICIT_ACCESS pListOfAccessEntries  OPTIONAL,
+                         IN ULONG cCountOfAuditEntries,
+                         IN PEXPLICIT_ACCESS pListOfAuditEntries  OPTIONAL,
+                         IN PSECURITY_DESCRIPTOR pOldSD  OPTIONAL,
+                         OUT PULONG pSizeNewSD,
+                         OUT PSECURITY_DESCRIPTOR* pNewSD)
+{
+    UNIMPLEMENTED;
+    return FALSE;
+}
+
+
+/*
+ * @unimplemented
+ */
+DWORD
+STDCALL
+BuildSecurityDescriptorA(IN PTRUSTEE_A pOwner  OPTIONAL,
+                         IN PTRUSTEE_A pGroup  OPTIONAL,
+                         IN ULONG cCountOfAccessEntries,
+                         IN PEXPLICIT_ACCESS pListOfAccessEntries  OPTIONAL,
+                         IN ULONG cCountOfAuditEntries,
+                         IN PEXPLICIT_ACCESS pListOfAuditEntries  OPTIONAL,
+                         IN PSECURITY_DESCRIPTOR pOldSD  OPTIONAL,
+                         OUT PULONG pSizeNewSD,
+                         OUT PSECURITY_DESCRIPTOR* pNewSD)
+{
+    UNIMPLEMENTED;
+    return FALSE;
+}
+
+
 /* EOF */
diff --git a/reactos/lib/advapi32/sec/sid.c b/reactos/lib/advapi32/sec/sid.c
index 93b0b6dc53a..c6f53384e15 100644
--- a/reactos/lib/advapi32/sec/sid.c
+++ b/reactos/lib/advapi32/sec/sid.c
@@ -1026,4 +1026,17 @@ CreateWellKnownSid(IN WELL_KNOWN_SID_TYPE WellKnownSidType,
     return FALSE;
 }
 
+
+/*
+ * @unimplemented
+ */
+BOOL STDCALL
+IsWellKnownSid(IN PSID pSid,
+               IN WELL_KNOWN_SID_TYPE WellKnownSidType)
+{
+    FIXME("unimplemented!\n", __FUNCTION__);
+    return FALSE;
+}
+
+
 /* EOF */