diff --git a/mozilla/makefile.win b/mozilla/makefile.win
index 8c2c57acb83..f1af60f3d05 100644
--- a/mozilla/makefile.win
+++ b/mozilla/makefile.win
@@ -80,6 +80,8 @@ DIRS = \
   rdf                           \
   webshell			\
   editor 			\
+!if defined(GC_LEAK_DETECTOR)
+  gc\boehm			\
 !endif
 !if defined(CLIENT_DIRS)
 # the following are associated with the browser
diff --git a/mozilla/xpcom/build/makefile.win b/mozilla/xpcom/build/makefile.win
index 0e9bf92c21c..44ac2b6260c 100644
--- a/mozilla/xpcom/build/makefile.win
+++ b/mozilla/xpcom/build/makefile.win
@@ -47,6 +47,9 @@ LCFLAGS=-D_IMPL_NS_COM        \
         -DWIN32_LEAN_AND_MEAN \
         -DEXPORT_XPT_API      \
         -DEXPORT_XPTC_API     \
+!ifdef GC_LEAK_DETECTOR
+	-DGC_LEAK_DETECTOR    \
+!endif
         -DEXPORT_XPTI_API
 
 CPP_OBJS =                             \