diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index fa3bf734e61..1a4097d75c8 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -460,7 +460,6 @@ rm -rf '$(CURDIR)'/tmp_check
 $(MKDIR_P) '$(CURDIR)'/tmp_check
 cd $(srcdir) && \
    TESTDIR='$(CURDIR)' PATH="$(bindir):$$PATH" PGPORT='6$(DEF_PGPORT)' \
-   top_builddir='$(top_builddir)' \
    PG_REGRESS='$(top_builddir)/src/test/regress/pg_regress' \
    $(PROVE) $(PG_PROVE_FLAGS) $(PROVE_FLAGS) $(if $(PROVE_TESTS),$(PROVE_TESTS),t/*.pl)
 endef