diff --git a/src/test/regress/expected/indirect_toast.out b/src/test/regress/expected/indirect_toast.out
index b05173c43b..ab1fa5e707 100644
--- a/src/test/regress/expected/indirect_toast.out
+++ b/src/test/regress/expected/indirect_toast.out
@@ -1,3 +1,9 @@
+--
+-- Tests for external toast datums
+--
+-- Other compression algorithms may cause the compressed data to be stored
+-- inline.  pglz guarantees that the data is externalized, so stick to it.
+SET default_toast_compression = 'pglz';
 CREATE TABLE indtoasttest(descr text, cnt int DEFAULT 0, f1 text, f2 text);
 INSERT INTO indtoasttest(descr, f1, f2) VALUES('two-compressed', repeat('1234567890',1000), repeat('1234567890',1000));
 INSERT INTO indtoasttest(descr, f1, f2) VALUES('two-toasted', repeat('1234567890',30000), repeat('1234567890',50000));
@@ -149,3 +155,4 @@ SELECT substring(indtoasttest::text, 1, 200) FROM indtoasttest;
 
 DROP TABLE indtoasttest;
 DROP FUNCTION update_using_indirect();
+RESET default_toast_compression;
diff --git a/src/test/regress/sql/indirect_toast.sql b/src/test/regress/sql/indirect_toast.sql
index efb1eb4e2f..9156a44b7d 100644
--- a/src/test/regress/sql/indirect_toast.sql
+++ b/src/test/regress/sql/indirect_toast.sql
@@ -1,3 +1,11 @@
+--
+-- Tests for external toast datums
+--
+
+-- Other compression algorithms may cause the compressed data to be stored
+-- inline.  pglz guarantees that the data is externalized, so stick to it.
+SET default_toast_compression = 'pglz';
+
 CREATE TABLE indtoasttest(descr text, cnt int DEFAULT 0, f1 text, f2 text);
 
 INSERT INTO indtoasttest(descr, f1, f2) VALUES('two-compressed', repeat('1234567890',1000), repeat('1234567890',1000));
@@ -59,3 +67,5 @@ SELECT substring(indtoasttest::text, 1, 200) FROM indtoasttest;
 
 DROP TABLE indtoasttest;
 DROP FUNCTION update_using_indirect();
+
+RESET default_toast_compression;