diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
index 1668119..96ba79c 100644
--- a/src/test/regress/pg_regress.c
+++ b/src/test/regress/pg_regress.c
@@ -1970,6 +1970,9 @@
 	 */
 	ifunc();
 
+	if (getenv("PG_REGRESS_DIFF_OPTS"))
+		pretty_diff_opts = getenv("PG_REGRESS_DIFF_OPTS");
+
 	while ((c = getopt_long(argc, argv, "hV", long_options, &option_index)) != -1)
 	{
 		switch (c)