diff --git a/makefiles/modules.inc.mk b/makefiles/modules.inc.mk
index b90f08284c..9d2f289bae 100644
--- a/makefiles/modules.inc.mk
+++ b/makefiles/modules.inc.mk
@@ -1,9 +1,11 @@
-ED = $(addprefix MODULE_,$(sort $(USEMODULE) $(USEPKG)))
+_ALLMODULES = $(sort $(USEMODULE) $(USEPKG))
+
+ED = $(addprefix MODULE_,$(_ALLMODULES))
 EXTDEFINES = $(addprefix -D,$(shell echo '$(ED)' | tr 'a-z-' 'A-Z_'))
 
 # filter "pseudomodules" from "real modules", but not "no_pseudomodules"
-NO_PSEUDOMODULES := $(filter $(NO_PSEUDOMODULES), $(sort $(USEMODULE) $(USEPKG)))
-REALMODULES = $(filter-out $(PSEUDOMODULES), $(sort $(USEMODULE) $(USEPKG))) $(NO_PSEUDOMODULES)
+NO_PSEUDOMODULES := $(filter $(NO_PSEUDOMODULES), $(_ALLMODULES))
+REALMODULES = $(filter-out $(PSEUDOMODULES), $(_ALLMODULES)) $(NO_PSEUDOMODULES)
 BASELIBS += $(REALMODULES:%=$(BINDIR)/%.a)
 
 CFLAGS += $(EXTDEFINES)