diff --git a/src/rev.h b/src/rev.h
--- a/src/rev.h
+++ b/src/rev.h
@@ -12,6 +12,7 @@
 
 extern const char _openttd_revision[];
 extern const char _openttd_build_date[];
+extern const char _openttd_build_date_short[];
 extern const char _openttd_revision_hash[];
 extern const char _openttd_revision_year[];
 extern const byte _openttd_revision_modified;