diff --git a/refpolicy/Rules.monolithic b/refpolicy/Rules.monolithic
index 7198dd3..c37f448 100644
--- a/refpolicy/Rules.monolithic
+++ b/refpolicy/Rules.monolithic
@@ -15,7 +15,7 @@ POLVER := policy.$(PV)
 APPFILES += $(APPDIR)/customizable_types $(INSTALLDIR)/booleans
 
 # for monolithic policy use all base and module to create policy
-ALL_MODULES := $(BASE_MODS) $(MOD_MODS)
+ALL_MODULES := $(strip $(BASE_MODS) $(MOD_MODS))
 
 ALL_INTERFACES := $(ALL_MODULES:.te=.if)
 ALL_TE_FILES := $(ALL_MODULES)