diff --git a/debian/tests/testsuite b/debian/tests/testsuite
index 35cb705..2adc2ac 100755
--- a/debian/tests/testsuite
+++ b/debian/tests/testsuite
@@ -7,4 +7,5 @@ case $USER in
   *) PGSUPERUSER=$USER ;;
 esac
 
-PGLOADER=pgloader PGSUPERUSER=$PGSUPERUSER pg_virtualenv make -C test prepare regress
+# use trust authentication to avoid scram failures on bullseye/buster/stretch/impish/focal/bionic
+PGLOADER=pgloader PGSUPERUSER=$PGSUPERUSER pg_virtualenv -i'-Atrust' make -C test prepare regress