diff --git a/chapter1.md b/chapter1.md
index e446d7b..2d3e75d 100644
--- a/chapter1.md
+++ b/chapter1.md
@@ -205,7 +205,7 @@ R    P    A C D  A          C
 ```
 
 Since this is a response `QR` is set, and so is `RA` to indicate that the
-server do support recursion. Looking at the remaining eight bytes of the reply,
+server does support recursion. Looking at the remaining eight bytes of the reply,
 we see that in addition to having a single question, we've also got a single
 answer record.