diff --git a/trainer_rules.mk b/trainer_rules.mk
index fdda9ba9b7..95e754abf4 100644
--- a/trainer_rules.mk
+++ b/trainer_rules.mk
@@ -7,5 +7,5 @@ AUTO_GEN_TARGETS += src/data/battle_partners.h
 AUTO_GEN_TARGETS += test/battle/trainer_control.h
 AUTO_GEN_TARGETS += src/data/debug_trainers.h
 
-%.h: %.party
+%.h: %.party $(TRAINERPROC)
 	$(CPP) $(CPPFLAGS) -traditional-cpp - < $< | $(TRAINERPROC) -o $@ -i $< -