--- feh-3.0/src/getopt.c.orig	2018-11-09 13:17:58.000000000 -0300
+++ feh-3.0/src/getopt.c	2018-11-09 19:54:00.251030262 -0300
@@ -36,6 +36,7 @@
 #endif
 
 #include <stdio.h>
+#include <string.h>
 
 /* Comment out all this code if we are using the GNU C Library, and are not
    actually compiling the library itself.  This code is part of the GNU C
