diff --git i/src/interfaces/libpq/Makefile w/src/interfaces/libpq/Makefile
index f19f272..266e3db 100644
--- i/src/interfaces/libpq/Makefile
+++ w/src/interfaces/libpq/Makefile
@@ -121,7 +121,7 @@ install: all installdirs install-lib
 	$(INSTALL_DATA) $(srcdir)/pqexpbuffer.h '$(DESTDIR)$(includedir_internal)'
 	$(INSTALL_DATA) $(srcdir)/pg_service.conf.sample '$(DESTDIR)$(datadir)/pg_service.conf.sample'
 
-check installcheck:
+installcheck:
 	$(MAKE) -C test $@
 
 installdirs: installdirs-lib
diff --git i/src/interfaces/libpq/test/Makefile w/src/interfaces/libpq/test/Makefile
index 964bb20..869a2f0 100644
--- i/src/interfaces/libpq/test/Makefile
+++ w/src/interfaces/libpq/test/Makefile
@@ -5,7 +5,7 @@ include $(top_builddir)/src/Makefile.global
 all: installcheck
 
 installcheck:
-	BINDIR='$(bindir)' SUBDIR='$(subdir)' $(SHELL) ./regress.sh
+	BINDIR='$(bindir)' PGPORT='$(DEF_PGPORT)' SUBDIR='$(subdir)' $(SHELL) ./regress.sh
 
 clean distclean maintainer-clean:
 	rm -f regress.out regress.diff