diff --git a/lib/Makefile.am b/lib/Makefile.am
index 21f58c497..1db291848 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -122,7 +122,7 @@ stat.c: xstat.in
 # On systems with glibc-2.1 or newer, the file is redundant, therefore we
 # avoid installing it.
 
-all-local: charset.alias ref-add.sed ref-del.sed lstat.c stat.c
+all-local: charset.alias ref-add.sed ref-del.sed lstat.c stat.c unlocked-io.h
 
 charset_alias = $(DESTDIR)$(libdir)/charset.alias
 charset_tmp = $(DESTDIR)$(libdir)/charset.tmp