--- a/Makefile
+++ b/Makefile
@@ -247,6 +247,9 @@ REGRESS += drop
 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-15-age -cdynamic_library_path=$(CURDIR)/debian/postgresql-15-age/usr/lib/postgresql/15/lib:/usr/lib/postgresql/15/lib -cmax_parallel_workers=0
 REGRESS_OPTS = --load-extension=age \
                --inputdir=$(ag_regress_dir) \
                --outputdir=$(ag_regress_dir) \
