diff --git a/src/scrut.c b/src/scrut.c
index a0ee93d..74a96dc 100644
--- a/src/scrut.c
+++ b/src/scrut.c
@@ -20,7 +20,7 @@
 #include <stdio.h> /* fprintf(3), stderr, NULL */
 #include <stdlib.h> /* EXIT_FAILURE, EXIT_SUCCESS */
 #include <string.h> /* memset(3), strchr(3) */
-#include <sysexits.h>
+#include <sysexits.h> /* EX_USAGE */
 #include <unistd.h> /* access(3), getopt(3), F_OK, R_OK, W_OK, X_OK */
 #include <sys/stat.h> /* lstat(3), stat struct, S_ISBLK, S_ISCHR, S_ISDIR,
                        * S_ISFIFO, S_ISGID, S_ISREG, S_ISLNK, S_ISSOCK,