diff --git a/src/test/perl/TestLib.pm b/src/test/perl/TestLib.pm
index d6c3eb8723..d4f9fc5f2b 100644
--- a/src/test/perl/TestLib.pm
+++ b/src/test/perl/TestLib.pm
@@ -104,13 +104,30 @@ BEGIN
 	delete $ENV{LC_ALL};
 	$ENV{LC_MESSAGES} = 'C';
 
+	delete $ENV{PGCHANNELBINDING};
+	delete $ENV{PGCLIENTENCODING};
 	delete $ENV{PGCONNECT_TIMEOUT};
 	delete $ENV{PGDATA};
 	delete $ENV{PGDATABASE};
+	delete $ENV{PGGSSENCMODE};
+	delete $ENV{PGGSSLIB};
 	delete $ENV{PGHOSTADDR};
+	delete $ENV{PGKRBSRVNAME};
+	delete $ENV{PGPASSFILE};
+	delete $ENV{PGPASSWORD};
+	delete $ENV{PGREQUIREPEER};
 	delete $ENV{PGREQUIRESSL};
 	delete $ENV{PGSERVICE};
+	delete $ENV{PGSERVICEFILE};
+	delete $ENV{PGSSLCERT};
+	delete $ENV{PGSSLCRL};
+	delete $ENV{PGSSLCRLDIR};
+	delete $ENV{PGSSLKEY};
+	delete $ENV{PGSSLMAXPROTOCOLVERSION};
+	delete $ENV{PGSSLMINPROTOCOLVERSION};
 	delete $ENV{PGSSLMODE};
+	delete $ENV{PGSSLROOTCERT};
+	delete $ENV{PGSSLSNI};
 	delete $ENV{PGUSER};
 	delete $ENV{PGPORT};
 	delete $ENV{PGHOST};