diff --git a/src/bin/pg_upgrade/.gitignore b/src/bin/pg_upgrade/.gitignore
index d24ec60184f..6fb644de7a9 100644
--- a/src/bin/pg_upgrade/.gitignore
+++ b/src/bin/pg_upgrade/.gitignore
@@ -4,5 +4,7 @@
 /delete_old_cluster.sh
 /analyze_new_cluster.bat
 /delete_old_cluster.bat
+/reindex_hash.sql
+/loadable_libraries.txt
 /log/
 /tmp_check/
diff --git a/src/bin/pg_upgrade/Makefile b/src/bin/pg_upgrade/Makefile
index 88232887081..d252e08d37a 100644
--- a/src/bin/pg_upgrade/Makefile
+++ b/src/bin/pg_upgrade/Makefile
@@ -32,12 +32,12 @@ uninstall:
 clean distclean maintainer-clean:
 	rm -f pg_upgrade$(X) $(OBJS)
 	rm -rf analyze_new_cluster.sh delete_old_cluster.sh log/ tmp_check/ \
+	       loadable_libraries.txt reindex_hash.sql \
 	       pg_upgrade_dump_globals.sql \
 	       pg_upgrade_dump_*.custom pg_upgrade_*.log
 
 check: test.sh all
 	MAKE=$(MAKE) bindir=$(bindir) libdir=$(libdir) EXTRA_REGRESS_OPTS="$(EXTRA_REGRESS_OPTS)" $(SHELL) $< --install
 
-# disabled because it upsets the build farm
-#installcheck: test.sh
-#	MAKE=$(MAKE) bindir=$(bindir) libdir=$(libdir) $(SHELL) $<
+# installcheck is not supported because there's no meaningful way to test
+# pg_upgrade against a single already-running server
diff --git a/src/bin/pg_upgrade/TESTING b/src/bin/pg_upgrade/TESTING
index 4ecfc5798e0..6831f679f66 100644
--- a/src/bin/pg_upgrade/TESTING
+++ b/src/bin/pg_upgrade/TESTING
@@ -1,3 +1,30 @@
+THE SHORT VERSION
+-----------------
+
+On non-Windows machines, you can execute the testing process
+described below by running
+	make check
+in this directory.  This will run the shell script test.sh, performing
+an upgrade from the version in this source tree to a new instance of
+the same version.
+
+To test an upgrade from a different version, you must have a built
+source tree for the old version as well as this version, and you
+must have done "make install" for both versions.  Then do:
+
+export oldsrc=...somewhere/postgresql	(old version's source tree)
+export oldbindir=...otherversion/bin	(old version's installed bin dir)
+export bindir=...thisversion/bin	(this version's installed bin dir)
+export libdir=...thisversion/lib	(this version's installed lib dir)
+sh test.sh
+
+In this case, you will have to manually eyeball the resulting dump
+diff for version-specific differences, as explained below.
+
+
+DETAILS
+-------
+
 The most effective way to test pg_upgrade, aside from testing on user
 data, is by upgrading the PostgreSQL regression database.
 
@@ -7,7 +34,7 @@ specific to each major version of Postgres.
 
 Here are the steps needed to create a regression database dump file:
 
-1)  Create and populate the regression database in the old cluster
+1)  Create and populate the regression database in the old cluster.
     This database can be created by running 'make installcheck' from
     src/test/regression.
 
@@ -60,22 +87,3 @@ steps:
 
 7)  Diff the regression database dump file with the regression dump
     file loaded into the old server.
-
-The shell script test.sh in this directory performs more or less this
-procedure.  You can invoke it by running
-
-    make check
-
-or by running
-
-    make installcheck
-
-if "make install" (or "make install-world") were done beforehand.
-When invoked without arguments, it will run an upgrade from the
-version in this source tree to a new instance of the same version.  To
-test an upgrade from a different version, invoke it like this:
-
-    make installcheck oldbindir=...otherversion/bin oldsrc=...somewhere/postgresql
-
-In this case, you will have to manually eyeball the resulting dump
-diff for version-specific differences, as explained above.
diff --git a/src/bin/pg_upgrade/test.sh b/src/bin/pg_upgrade/test.sh
index 841da034b09..f4556341f32 100644
--- a/src/bin/pg_upgrade/test.sh
+++ b/src/bin/pg_upgrade/test.sh
@@ -170,18 +170,32 @@ createdb "$dbname2" || createdb_status=$?
 createdb "$dbname3" || createdb_status=$?
 
 if "$MAKE" -C "$oldsrc" installcheck; then
-	pg_dumpall --no-sync -f "$temp_root"/dump1.sql || pg_dumpall1_status=$?
+	oldpgversion=`psql -X -A -t -d regression -c "SHOW server_version_num"`
+
+	# before dumping, get rid of objects not existing in later versions
 	if [ "$newsrc" != "$oldsrc" ]; then
-		oldpgversion=`psql -X -A -t -d regression -c "SHOW server_version_num"`
 		fix_sql=""
 		case $oldpgversion in
 			804??)
-				fix_sql="UPDATE pg_proc SET probin = replace(probin::text, '$oldsrc', '$newsrc')::bytea WHERE probin LIKE '$oldsrc%'; DROP FUNCTION public.myfunc(integer);"
+				fix_sql="DROP FUNCTION public.myfunc(integer); DROP FUNCTION public.oldstyle_length(integer, text);"
 				;;
-			900??)
-				fix_sql="SET bytea_output TO escape; UPDATE pg_proc SET probin = replace(probin::text, '$oldsrc', '$newsrc')::bytea WHERE probin LIKE '$oldsrc%';"
+			*)
+				fix_sql="DROP FUNCTION public.oldstyle_length(integer, text);"
 				;;
-			901??)
+		esac
+		psql -X -d regression -c "$fix_sql;" || psql_fix_sql_status=$?
+	fi
+
+	pg_dumpall --no-sync -f "$temp_root"/dump1.sql || pg_dumpall1_status=$?
+
+	if [ "$newsrc" != "$oldsrc" ]; then
+		# update references to old source tree's regress.so etc
+		fix_sql=""
+		case $oldpgversion in
+			804??)
+				fix_sql="UPDATE pg_proc SET probin = replace(probin::text, '$oldsrc', '$newsrc')::bytea WHERE probin LIKE '$oldsrc%';"
+				;;
+			*)
 				fix_sql="UPDATE pg_proc SET probin = replace(probin, '$oldsrc', '$newsrc') WHERE probin LIKE '$oldsrc%';"
 				;;
 		esac