diff --git a/bootstrap.conf b/bootstrap.conf
index 9b2de22..3ab2c8b 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -19,6 +19,7 @@
 # gnulib modules used by this package.
 gnulib_modules='
 announce-gen
+argmatch
 binary-io
 c-stack
 config-h
diff --git a/src/util.c b/src/util.c
index 65b06e9..d27d202 100644
--- a/src/util.c
+++ b/src/util.c
@@ -19,6 +19,7 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 #include "diff.h"
+#include "argmatch.h"
 #include <dirname.h>
 #include <error.h>
 #include <system-quote.h>
@@ -561,6 +562,7 @@ static const char *const indicator_name[]=
   {
     "lc", "rc", "ec", "rs", "hd", "ad", "de", "ln", NULL
   };
+ARGMATCH_VERIFY (indicator_name, color_indicator);

 static const char *color_palette;