diff --git a/src/nls-global.mk b/src/nls-global.mk
index dfff472cb3f..73a6db10a1d 100644
--- a/src/nls-global.mk
+++ b/src/nls-global.mk
@@ -142,8 +142,13 @@ init-po: po/$(CATALOG_NAME).pot
 # For performance reasons, only calculate these when the user actually
 # requested update-po or a specific file.
 ifneq (,$(filter update-po %.po.new,$(MAKECMDGOALS)))
+ifdef PGXS
+ALL_LANGUAGES := $(shell find . -name '*.po' -print | sed 's,^.*/\([^/]*\).po$$,\1,' | LC_ALL=C sort -u)
+all_compendia := $(shell find . -name '*.po' -print | LC_ALL=C sort)
+else
 ALL_LANGUAGES := $(shell find $(top_srcdir) -name '*.po' -print | sed 's,^.*/\([^/]*\).po$$,\1,' | LC_ALL=C sort -u)
 all_compendia := $(shell find $(top_srcdir) -name '*.po' -print | LC_ALL=C sort)
+endif
 else
 ALL_LANGUAGES = $(AVAIL_LANGUAGES)
 all_compendia = FORCE