diff --git a/Rules.modular b/Rules.modular
index a63a006..e832d79 100644
--- a/Rules.modular
+++ b/Rules.modular
@@ -30,8 +30,7 @@ vpath %.te $(all_layers)
 vpath %.if $(all_layers)
 vpath %.fc $(all_layers)
 
-# broken in make 3.81:
-#.SECONDARY:
+.SECONDARY: $(addprefix $(tmpdir)/,$(mod_pkgs:.pp=.mod)) $(addprefix $(tmpdir)/,$(mod_pkgs:.pp=.mod.fc))
 
 ########################################
 #