-TARGETS := $(foreach fmt,html txt ps pdf,developers-reference.$(fmt)) \
- $(foreach langext,.fr .ja, \
- $(foreach fmt,html txt ps pdf,developers-reference$(langext).$(fmt)))
+TARGETS := $(foreach fmt,html txt pdf,developers-reference.$(fmt)) \
+ $(filter-out developers-reference.ja.pdf, \
+ $(foreach langext,.fr, \
+ $(foreach fmt,html txt,developers-reference$(langext).$(fmt))))