diff --git a/extra/http/client/client-tests.factor b/extra/http/client/client-tests.factor
index 9ad805b81b..db90f746ac 100755
--- a/extra/http/client/client-tests.factor
+++ b/extra/http/client/client-tests.factor
@@ -17,7 +17,7 @@ tuple-syntax namespaces ;
         path: "/index.html"
         version: "1.1"
         cookies: V{ }
-        header: H{ { "connection" "close" } }
+        header: H{ { "connection" "close" } { "user-agent" "Factor http.client vocabulary" } }
     }
 ] [
     [
@@ -35,7 +35,7 @@ tuple-syntax namespaces ;
         path: "/index.html"
         version: "1.1"
         cookies: V{ }
-        header: H{ { "connection" "close" } }
+        header: H{ { "connection" "close" } { "user-agent" "Factor http.client vocabulary" } }
     }
 ] [
     [
diff --git a/extra/http/client/client.factor b/extra/http/client/client.factor
index cec1bb931a..c455c8c5f1 100755
--- a/extra/http/client/client.factor
+++ b/extra/http/client/client.factor
@@ -4,7 +4,7 @@ USING: assocs http kernel math math.parser namespaces sequences
 io io.sockets io.streams.string io.files io.timeouts strings
 splitting calendar continuations accessors vectors math.order
 io.encodings.8-bit io.encodings.binary io.streams.duplex
-fry debugger inspector ;
+fry debugger inspector ascii ;
 IN: http.client
 
 : max-redirects 10 ;
@@ -37,8 +37,12 @@ SYMBOL: redirects
 
 PRIVATE>
 
+: read-chunk-size ( -- n )
+    read-crlf ";" split1 drop [ blank? ] right-trim
+    hex> [ "Bad chunk size" throw ] unless* ;
+
 : read-chunks ( -- )
-    read-crlf ";" split1 drop hex> dup { f 0 } member?
+    read-chunk-size dup zero?
     [ drop ] [ read % read-crlf "" assert= read-chunks ] if ;
 
 : read-response-body ( response -- response data )
diff --git a/extra/http/http.factor b/extra/http/http.factor
index bc79424552..7587cb0fe9 100755
--- a/extra/http/http.factor
+++ b/extra/http/http.factor
@@ -256,7 +256,8 @@ cookies ;
         H{ } clone >>header
         H{ } clone >>query
         V{ } clone >>cookies
-        "close" "connection" set-header ;
+        "close" "connection" set-header
+        "Factor http.client vocabulary" "user-agent" set-header ;
 
 : query-param ( request key -- value )
     swap query>> at ;