I need to escape \n so on output I really get newline or tab

$ perl -p -e 's/e/a/ge'

now I want each e to be substituted with \n

$ perl -p -e 's/e/\n/ge'

but even \n gives me an error.

this was a simplified example. In real script(makefile) I have

substitute := perl -p -e 's/@([^@]+)@/defined $$ENV{$$1} ? $$ENV{$$1} : $$1/ge'

and in target I have such a nice command

$(substitute) $< > $@

and if the input file for perl contains \n at output I will see it literally... I want to have real newline.