diff -ur zziplib-0.13.69/zzip/plugin.c zziplib-src/zzip/plugin.c
--- zziplib-0.13.69/zzip/plugin.c	Sat Mar 17 21:46:45 2018
+++ zziplib-src/zzip/plugin.c	Sun Mar 18 08:04:42 2018
@@ -41,7 +41,7 @@
     return st.st_size;
 }
 
-static const struct zzip_plugin_io default_io = {
+static struct zzip_plugin_io default_io = {
     &open,
     &close,
     &_zzip_read,
