--- a/Makefile
+++ b/Makefile
@@ -114,6 +114,9 @@ REGRESS = scan \
 srcdir=`pwd`
 
 ag_regress_dir = $(srcdir)/regress
+# Set extension_destdir/dynamic_library_path
+# Set max_parallel_workers to suppress a "CONTEXT:  parallel worker" in regression tests
+export PGOPTIONS = -cextension_destdir=$(CURDIR)/debian/postgresql-13-age -cdynamic_library_path=$(CURDIR)/debian/postgresql-13-age/usr/lib/postgresql/13/lib:/usr/lib/postgresql/13/lib -cmax_parallel_workers=0
 REGRESS_OPTS = --load-extension=age --inputdir=$(ag_regress_dir) --outputdir=$(ag_regress_dir) --temp-instance=$(ag_regress_dir)/instance --port=61958 --encoding=UTF-8 --temp-config $(ag_regress_dir)/age_regression.conf
 
 ag_regress_out = instance/ log/ results/ regression.*
