diff --git a/collects/net/doc.txt b/collects/net/doc.txt
index d7098cdfc8..2d425adb51 100644
--- a/collects/net/doc.txt
+++ b/collects/net/doc.txt
@@ -37,7 +37,7 @@ _url struct_
 > url-port : url -> (union false/c number?)
 > url-path-absolute? : url -> boolean?
 > url-path : url -> (listof path/param?)
-> url-query : url -> (listof (cons/c symbol? string?))
+> url-query : url -> (listof (cons/c symbol? (union false/c string?)))
 > url-fragment : url -> (union false/c string?)
 > url? : any -> boolean
 > make-url : ...as-above.. -> url
diff --git a/collects/net/uri-codec-unit.ss b/collects/net/uri-codec-unit.ss
index df5018a8f1..6769444fad 100644
--- a/collects/net/uri-codec-unit.ss
+++ b/collects/net/uri-codec-unit.ss
@@ -305,65 +305,39 @@ JALQefhDMCATcl2/bZL0bw==
   ;; http://www.w3.org/TR/html401/appendix/notes.html#ampersands-in-uris
   ;; listof (cons symbol string) -> string
   (define (alist->form-urlencoded args)
-    (let* ([mode (current-alist-separator-mode)]
+    (let* ([sep (if (eq? (current-alist-separator-mode) 'amp) "&" ";")]
            [format-one
             (lambda (arg)
-              (let* ([name (car arg)]
-                     [value (cdr arg)])
-                (string-append (form-urlencoded-encode (symbol->string name))
-                               "="
-                               (form-urlencoded-encode value))))]
-           [strs (let loop ([args args])
-                   (cond
-                     [(null? args) null]
-                     [(null? (cdr args)) (list (format-one (car args)))]
-                     [else (list* (format-one (car args))
-                                  (if (eq? mode 'amp) "&" ";")
-                                  (loop (cdr args)))]))])
+              (let* ([name  (car arg)]
+                     [value (cdr arg)]
+                     [name  (form-urlencoded-encode (symbol->string name))]
+                     [value (and value (form-urlencoded-encode value))])
+                (if value (string-append name "=" value) name)))]
+           [strs (if (null? args)
+                   '()
+                   (cons (format-one (car args))
+                         (apply append
+                                (map (lambda (a) (list sep (format-one a)))
+                                     (cdr args)))))])
       (apply string-append strs)))
 
   ;; string -> listof (cons string string)
   ;; http://www.w3.org/TR/html401/appendix/notes.html#ampersands-in-uris
   (define (form-urlencoded->alist str)
-    (define key-regexp #rx"[^=]*")
-    (define value-regexp (case (current-alist-separator-mode)
-                           [(semi) #rx"[^;]*"]
-                           [(amp) #rx"[^&]*"]
-                           [else #rx"[^&;]*"]))
-    (define (next-key str start)
-      (and (< start (string-length str))
-           (match (regexp-match-positions key-regexp str start)
-             [((start . end))
-              (vector (let ([s (form-urlencoded-decode
-                                (substring str start end))])
-                        (string->symbol s))
-                      (add1 end))]
-             [#f #f])))
-    (define (next-value str start)
-      (and (< start (string-length str))
-           (match (regexp-match-positions value-regexp str start)
-             [((start . end))
-              (vector (form-urlencoded-decode (substring str start end))
-                      (add1 end))]
-             [#f #f])))
-    (define (next-pair str start)
-      (match (next-key str start)
-        [#(key start)
-         (match (next-value str start)
-           [#(value start)
-            (vector (cons key value) start)]
-           [#f
-            (vector (cons key "") (string-length str))])]
-        [#f #f]))
-    (let loop ([start 0]
-               [end (string-length str)]
-               [make-alist (lambda (x) x)])
-      (if (>= start end)
-        (make-alist '())
-        (match (next-pair str start)
-          [#(pair next-start)
-           (loop next-start end (lambda (x) (make-alist (cons pair x))))]
-          [#f (make-alist '())]))))
+    (define keyval-regexp #rx"^([^=]*)(?:=(.*))?$")
+    (define value-regexp
+      (case (current-alist-separator-mode)
+        [(semi) #rx"[;]"]
+        [(amp) #rx"[&]"]
+        [else #rx"[&;]"]))
+    (if (equal? "" str)
+      '()
+      (map (lambda (keyval)
+             (let ([m (regexp-match keyval-regexp keyval)]) ; cannot fail
+               (cons (string->symbol (form-urlencoded-decode (cadr m)))
+                     ;; can be #f for no "=..." part
+                     (and (caddr m) (form-urlencoded-decode (caddr m))))))
+           (regexp-split value-regexp str))))
 
   (define current-alist-separator-mode
     (make-parameter 'amp-or-semi
diff --git a/collects/net/url-structs.ss b/collects/net/url-structs.ss
index 87a76c341b..7e65e00122 100644
--- a/collects/net/url-structs.ss
+++ b/collects/net/url-structs.ss
@@ -12,7 +12,7 @@
                 [port (or/c false/c number?)]
                 [path-absolute? boolean?]
                 [path (listof path/param?)]
-                [query (listof (cons/c symbol? string?))]
+                [query (listof (cons/c symbol? (or/c string? false/c)))]
                 [fragment (or/c false/c string?)]))
    (struct path/param ([path (or/c string? (symbols 'up 'same))]
                        [param (listof string?)]))))
diff --git a/collects/tests/mzscheme/net.ss b/collects/tests/mzscheme/net.ss
index 2cfee9d1e5..f8f9cc66b2 100644
--- a/collects/tests/mzscheme/net.ss
+++ b/collects/tests/mzscheme/net.ss
@@ -132,7 +132,7 @@
   (test '((key . "value")) form-urlencoded->alist "key=value")
   (test '((key . "hello there")) form-urlencoded->alist "key=hello+there")
   (test '((key . "a value")) form-urlencoded->alist "key=a%20value")
-  (test '((key . ""))  form-urlencoded->alist "key")
+  (test '((key . #f))  form-urlencoded->alist "key")
   (test '((key1 . "value 1") (key2 . "value 2")) form-urlencoded->alist "key1=value+1&key2=value+2"))
 
 ;;
@@ -300,6 +300,19 @@
         "http://foo:/abc/def.html")
   (set-url:os-type! 'unix)
 
+  ;; see PR8809 (value-less keys in the query part)
+  (test-s->u #("http" #f "foo.bar" #f #t (#("baz")) ((ugh . #f)) #f)
+             "http://foo.bar/baz?ugh")
+  (test-s->u #("http" #f "foo.bar" #f #t (#("baz")) ((ugh . "")) #f)
+             "http://foo.bar/baz?ugh=")
+  (test-s->u #("http" #f "foo.bar" #f #t (#("baz")) ((ugh . #f) (x . "y") (|1| . "2")) #f)
+             "http://foo.bar/baz?ugh;x=y;1=2")
+  (parameterize ([current-alist-separator-mode 'amp])
+    (test-s->u #("http" #f "foo.bar" #f #t (#("baz")) ((ugh . #f) (x . "y") (|1| . "2")) #f)
+             "http://foo.bar/baz?ugh&x=y&1=2"))
+  (test-s->u #("http" #f "foo.bar" #f #t (#("baz")) ((ugh . "") (x . "y") (|1| . "2")) #f)
+             "http://foo.bar/baz?ugh=;x=y;1=2")
+
   ;; test case sensitivity
   (test #("http" "ROBBY" "www.drscheme.org" 80 #t (#("INDEX.HTML" "XXX")) ((T . "P")) "YYY")
         string->url/vec