1 files changed, 4 insertions, 4 deletions
diff --git a/stream.c b/stream.c
index a4560f05..64ca8888 100644
--- a/stream.c
+++ b/stream.c
@@ -860,9 +860,9 @@ static val stdio_put_buf(val stream, val buf, cnum pos)
   ucnum len = c_unum(length_buf(buf));
   mem_t *ptr = buf_get(buf, self);
   struct stdio_handle *h = coerce(struct stdio_handle *, stream->co.handle);
-  if ((size_t) len != len)
+  if ((size_t) len != len || len > INT_PTR_MAX)
     uw_throwf(error_s, lit("~a: buffer too large"), self, nao);
-  if (pos >= len)
+  if (convert(ucnum, pos) >= len)
     return num(len);
   errno = 0;
   if (h->f != 0) {
@@ -880,9 +880,9 @@ static val stdio_fill_buf(val stream, val buf, cnum pos)
   ucnum len = c_unum(length_buf(buf));
   mem_t *ptr = buf_get(buf, self);
   struct stdio_handle *h = coerce(struct stdio_handle *, stream->co.handle);
-  if ((size_t) len != len)
+  if ((size_t) len != len || len > INT_PTR_MAX)
     uw_throwf(error_s, lit("~a: buffer too large"), self, nao);
-  if (pos >= len)
+  if (convert(ucnum, pos) >= len)
     return num(len);
   errno = 0;
   if (h->f != 0) {