diff --git a/src/putty/unix/uxsftp.c b/src/putty/unix/uxsftp.c
index f078d97..05ec2ff 100644
--- a/src/putty/unix/uxsftp.c
+++ b/src/putty/unix/uxsftp.c
@@ -211,7 +211,7 @@ int read_from_file(RFile *f, void *buffer, int length)
 #if 1
     if (f->state == ok && !f->remaining_) {
         fznotify1(sftp_io_nextbuf, 0);
-        char const* s = priority_read();
+        char *s = priority_read();
         if (s[1] == '-') {
             f->state = error;
             return -1;
@@ -220,11 +220,11 @@ int read_from_file(RFile *f, void *buffer, int length)
             f->state = eof;
         }
         else {
-            char const* p = s + 1;
+            char *p = s + 1;
             f->buffer_ = f->memory_ + next_int(&p);
             f->remaining_ = (int)next_int(&p);
         }
-        sfree(s);
+        sfree((void *)s);
     }
     if (f->state == eof) {
         return 0;