diff -ur chntpw-140201.orig/chntpw.c chntpw-140201/chntpw.c
--- chntpw-140201.orig/chntpw.c	2020-06-08 14:21:55.839494887 +0000
+++ chntpw-140201/chntpw.c	2020-06-08 14:22:29.922115922 +0000
@@ -1026,7 +1026,8 @@
   int mode = HMODE_INFO;
   extern int /* opterr, */ optind;
   extern char* optarg;
-  char *filename,c;
+  char *filename;
+  signed char c;
   char *who = "Administrator";
   char iwho[100];
   FILE *ch;     /* Write out names of touched files to this */
diff -ur chntpw-140201.orig/sampasswd.c chntpw-140201/sampasswd.c
--- chntpw-140201.orig/sampasswd.c	2020-06-08 14:21:49.661563576 +0000
+++ chntpw-140201/sampasswd.c	2020-06-08 14:22:21.009215027 +0000
@@ -140,7 +140,7 @@
   int first = 0;
   int ret, wret, il;
   char *hivename;
-  char c;
+  signed char c;
   char *usr = NULL;
 
   char *options = "rlHu:vNEthaf";
diff -ur chntpw-140201.orig/samusrgrp.c chntpw-140201/samusrgrp.c
--- chntpw-140201.orig/samusrgrp.c	2020-06-08 14:21:47.330589493 +0000
+++ chntpw-140201/samusrgrp.c	2020-06-08 14:22:19.218234941 +0000
@@ -176,7 +176,7 @@
   int human = 0;
   int ret, wret, il;
   char *hivename;
-  char c;
+  signed char c;
   char *usr = NULL;
   char *grp = NULL;