diff --git a/src/bin/pg_upgrade/nls.mk b/src/bin/pg_upgrade/nls.mk
index 06308bdf788..01aaa6873b7 100644
--- a/src/bin/pg_upgrade/nls.mk
+++ b/src/bin/pg_upgrade/nls.mk
@@ -9,4 +9,5 @@ GETTEXT_FLAGS    = \
     pg_fatal:1:c-format \
     pg_log:2:c-format \
     prep_status:1:c-format \
+    prep_status_progress:1:c-format \
     report_status:2:c-format