diff --git a/mozilla/config/WIN32 b/mozilla/config/WIN32
index 6e68f6d7bf6..42cdac8ea25 100644
--- a/mozilla/config/WIN32
+++ b/mozilla/config/WIN32
@@ -77,7 +77,9 @@ OS_LFLAGS=
 !endif
 !endif
 
+!ifndef MODULAR_NETLIB
 OPTIMIZER=$(OPTIMIZER) -DCookieManagement -DSingleSignon
+!endif
 
 #//------------------------------------------------------------------------
 #//