diff --git a/project/pycgen.mk b/project/pycgen.mk
index af02e96..27e7dbd 100644
--- a/project/pycgen.mk
+++ b/project/pycgen.mk
@@ -55,6 +55,10 @@ $(PYCOMPILE_DIR)/$(PYDIST_PYCDIR)/./urllib/%.py: $(SOURCE_DIR)/Lib/urllib/%.py $
 		PYCOPY_DSTDIR=$(PYCOMPILE_DIR)/$(PYDIST_PYCDIR)/urllib \
 		$(PYCOPY) $<
 
+$(PYDIST_PYCDIR)/./lib2to3/tests/data/%.pyx: $(PYCOMPILE_DIR)/tree.tag
+$(PYDIST_PYCDIR)/./lib2to3/tests/data/%.pyx: $(PYDIST_PYCDIR)/./lib2to3/tests/data/%.py
+		touch $@
+
 PYCGEN_SRCS = \
 	$(PYCGEN_CFGDAT) \
 	$(PYCGEN_PYSRCS) \