diff --git a/Makefile b/Makefile
index 07a0f45..cce47d3 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,10 @@
 include pgxntool/base.mk
 
+# Explicit rather than relying on auto-detect (which enables this whenever
+# test/build/*.sql exists) so an accidental deletion of test/build/'s
+# contents is a hard error instead of the check silently disappearing.
+PGXNTOOL_ENABLE_TEST_BUILD = yes
+
 testdeps: test_extension
 test_extension: $(DESTDIR)$datadir)/extension/extension_drop_test.control $(wildcard $(TESTDIR)/*)
 $(DESTDIR)$datadir)/extension/extension_drop_test.control:
diff --git a/test/build/build.sql b/test/build/build.sql
new file mode 100644
index 0000000..bf3de74
--- /dev/null
+++ b/test/build/build.sql
@@ -0,0 +1,25 @@
+\set ECHO none
+BEGIN;
+\i test/pgxntool/psql.sql
+
+/*
+ * Install dependencies via CREATE EXTENSION, not \i: this is a real,
+ * already-published dependency being installed normally, not the extension
+ * whose raw install script this file exists to test line-by-line below.
+ */
+CREATE EXTENSION IF NOT EXISTS cat_tools;
+
+/*
+ * Suppress NOTICEs from the raw install script itself (e.g. "%TYPE converted
+ * to ..." with a version-specific source-file LOCATION line) so this file's
+ * expected output stays stable across PostgreSQL minor versions instead of
+ * capturing verbose, version-dependent messages.
+ */
+SET client_min_messages = WARNING;
+
+\echo
+\echo INSTALL
+\t
+\i sql/extension_drop.sql
+
+\echo # TRANSACTION INTENTIONALLY LEFT OPEN
diff --git a/test/expected/zzz_build.out b/test/build/expected/build.out
similarity index 96%
rename from test/expected/zzz_build.out
rename to test/build/expected/build.out
index c66ee3c..44215eb 100644
--- a/test/expected/zzz_build.out
+++ b/test/build/expected/build.out
@@ -19,6 +19,4 @@ INSTALL
 
  
 
- 
-
 # TRANSACTION INTENTIONALLY LEFT OPEN
diff --git a/test/sql/zzz_build.sql b/test/sql/zzz_build.sql
deleted file mode 100644
index 354c480..0000000
--- a/test/sql/zzz_build.sql
+++ /dev/null
@@ -1,12 +0,0 @@
-\set ECHO none
-BEGIN;
-\i test/pgxntool/psql.sql
-
-CREATE EXTENSION IF NOT EXISTS cat_tools;
-
-\echo
-\echo INSTALL
-\t
-\i sql/extension_drop.sql
-
-\echo # TRANSACTION INTENTIONALLY LEFT OPEN