diff --git a/client/maxadmin.c b/client/maxadmin.c
index 3866aa164..d253661db 100644
--- a/client/maxadmin.c
+++ b/client/maxadmin.c
@@ -241,7 +241,7 @@ main(int argc, char **argv)
     bool use_unix_socket = false;
 
     int option_index = 0;
-    char c;
+    int c;
     while ((c = getopt_long(argc, argv, "h:p::P:u:S:v?ei",
                             long_options, &option_index)) >= 0)
     {
diff --git a/server/modules/routing/binlogrouter/maxbinlogcheck.c b/server/modules/routing/binlogrouter/maxbinlogcheck.c
index 953c1053a..ad02d5a93 100644
--- a/server/modules/routing/binlogrouter/maxbinlogcheck.c
+++ b/server/modules/routing/binlogrouter/maxbinlogcheck.c
@@ -88,7 +88,7 @@ int main(int argc, char **argv)
     char *key_file = NULL;
     char *aes_algo = NULL;
     int report_header = 0;
-    char c;
+    int c;
     BINLOG_FILE_FIX binlog_file = {0, false, false};
 
 #ifdef HAVE_GLIBC