diff --git a/calendar/libxpical/Makefile.in b/calendar/libxpical/Makefile.in
index 408ae6b735c..a0151efcf7d 100644
--- a/calendar/libxpical/Makefile.in
+++ b/calendar/libxpical/Makefile.in
@@ -66,4 +66,7 @@ CPPSRCS		= \
 
 EXTRA_DSO_LDOPTS += $(MOZ_COMPONENT_LIBS) -lical -licalss
 
+OS_COMPILE_CXXFLAGS += -DICAL_DEBUG 
+#-DICAL_DEBUG_ALL
+
 include $(topsrcdir)/config/rules.mk