diff --git a/src/interfaces/ecpg/test/Makefile b/src/interfaces/ecpg/test/Makefile
index 28f02fe..ea7de34 100644
--- a/src/interfaces/ecpg/test/Makefile
+++ b/src/interfaces/ecpg/test/Makefile
@@ -86,3 +86,14 @@ checktcp: all
 
 installcheck: all
 	./pg_regress $(REGRESS_OPTS) --bindir='$(bindir)' $(pg_regress_locale_flags) $(THREAD) --schedule=$(srcdir)/ecpg_schedule
+
+# Versions of the check tests that include the twophase commit test.
+# It only makes sense to run these if set up to use prepared transactions,
+# via TEMP_CONFIG for the check case, or via the postgresql.conf for the
+# installcheck case.
+
+installcheck-prepared-txns: all
+	./pg_regress $(REGRESS_OPTS) --bindir='$(bindir)' $(pg_regress_locale_flags) $(THREAD) --schedule=$(srcdir)/ecpg_schedule sql/twophase
+
+check-prepared-txns: all
+	$(with_temp_install) ./pg_regress $(REGRESS_OPTS) --temp-instance=./tmp_check $(TEMP_CONF) --bindir= $(pg_regress_locale_flags) $(THREAD) --schedule=$(srcdir)/ecpg_schedule sql/twophase
diff --git a/src/interfaces/ecpg/test/ecpg_schedule b/src/interfaces/ecpg/test/ecpg_schedule
index 206f712..c3ec125 100644
--- a/src/interfaces/ecpg/test/ecpg_schedule
+++ b/src/interfaces/ecpg/test/ecpg_schedule
@@ -46,7 +46,6 @@ test: sql/indicators
 test: sql/oldexec
 test: sql/quote
 test: sql/show
-test: sql/twophase
 test: sql/insupd
 test: sql/parser
 test: thread/thread