1 files changed, 2 insertions, 2 deletions
diff --git a/sys/libn/bufio.c b/sys/libn/bufio.c
index 05b6068..cde56b7 100644
--- a/sys/libn/bufio.c
+++ b/sys/libn/bufio.c
@@ -75,8 +75,8 @@ getbyte:
 error
 bufio·ungetbyte(io·Buffer *buf, byte c)
 {
-    buf->state ^= bufio·end;
-    if (buf->state & bufio·rdr) {
+    buf->state &= ~bufio·end;
+    if (!(buf->state & bufio·rdr)) {
         errorf("attempted to unget on non-active reader");
         return bufio·err;
     }