diff --git a/winsup/Makefile.in b/winsup/Makefile.in
index 29ef22abe..1fdf93aa9 100644
--- a/winsup/Makefile.in
+++ b/winsup/Makefile.in
@@ -33,6 +33,7 @@ endif
 else
 tooldir:=$(exec_prefix)/$(target_alias)
 endif
+datarootdir:=@datarootdir@
 datadir:=@datadir@
 infodir:=@infodir@
 includedir:=@includedir@