--- a/Makefile.in
+++ b/Makefile.in
@@ -281,7 +281,7 @@ top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 SUBDIRS = src
-zshcompletiondir = ${datarootdir}/zsh/site-functions
+zshcompletiondir = ${DESTDIR}/${datarootdir}/zsh/site-functions
 zshcompletion = ${zshcompletiondir}/_parallel
 EXTRA_DIST = CITATION CITATION.cff CREDITS LICENSES/CC-BY-SA-4.0.txt LICENSES/GFDL-1.3-or-later.txt LICENSES/GPL-3.0-or-later.txt
 all: config.h
@@ -929,9 +929,9 @@ pack_unpack_and_test_build:
 	cd parallel-$(YYYYMMDD) && \
 	./configure && make -j && sudo make -j install
 install-data-hook:
-	mkdir -p ${datarootdir}/bash-completion/completions
+	mkdir -p ${DESTDIR}/${datarootdir}/bash-completion/completions
 	mkdir -p ${zshcompletiondir}
-	parallel --shell-completion bash > ${datarootdir}/bash-completion/completions/parallel
+	./src/parallel --shell-completion bash > ${DESTDIR}/${datarootdir}/bash-completion/completions/parallel
 	echo '#compdef parallel' > ${zshcompletion}
 	echo '(( $$+functions[_comp_parallel] )) ||' >> ${zshcompletion}
 	echo '  eval "$$(parallel --shell-completion auto)" &&' >> ${zshcompletion}