diff --git a/unistd.in.h b/unistd.in.h
index b82be83..9df3f13 100644
--- a/unistd.in.h
+++ b/unistd.in.h
@@ -125,7 +125,11 @@
 
 /* Get getopt(), optarg, optind, opterr, optopt.
    But avoid namespace pollution on glibc systems.  */
-#if @GNULIB_UNISTD_H_GETOPT@ && !defined __GLIBC__ && !defined _GL_SYSTEM_GETOPT
+/* Also, don't include <getopt.h> inside libgettextpo, because we use
+   the getopt module only in gettext-tools/gnulib-lib/, not in
+   gettext-tools/libgettextpo/, but there is only a single
+   GNULIB_UNISTD_H_GETOPT variable for both.  */
+#if @GNULIB_UNISTD_H_GETOPT@ && !defined GTPO_CONFIG_H && !defined __GLIBC__ && !defined _GL_SYSTEM_GETOPT
 # define __need_getopt
 # include <getopt.h>
 #endif