diff --git a/collects/net/dns.rkt b/collects/net/dns.rkt
index f2d8ba5f48..729a1d0623 100644
--- a/collects/net/dns.rkt
+++ b/collects/net/dns.rkt
@@ -214,6 +214,11 @@
                                           timeout))
                             (lambda (v) (retry (* timeout 2)))))))
       (lambda () (udp-close udp))))
+
+  (parse-reply query reply))
+
+;; Parse a DNS query reply
+(define (parse-reply query reply)
   ;; First two bytes must match sent message id:
   (unless (and (= (car reply)  (car query))
                (= (cadr reply) (cadr query)))
@@ -361,25 +366,32 @@
   (or (try-forwarding
        (lambda (nameserver)
          (let-values ([(auth? qds ans nss ars reply) (dns-query/cache nameserver addr 'mx 'in)])
-           (values (let loop ([ans ans][best-pref +inf.0][exchanger #f])
-                     (cond
-                       [(null? ans)
-                        (or (and exchanger (bytes->string/latin-1 exchanger))
-                            ;; Does 'soa mean that the input address is fine?
-                            (and (ormap (lambda (ns) (eq? (rr-type ns) 'soa))
-                                        nss)
-                                 addr))]
-                       [else
-                        (define d (rr-data (car ans)))
-                        (define pref (octet-pair->number (car d) (cadr d)))
-                        (if (< pref best-pref)
-                            (let-values ([(name start) (parse-name (cddr d) reply)])
-                              (loop (cdr ans) pref name))
-                            (loop (cdr ans) best-pref exchanger))]))
-                   ars auth?)))
+           (values (parse-mx-response ans nss reply addr) ars auth?)))
        nameserver)
       (error 'dns-get-mail-exchanger "bad address")))
 
+;; helper that parses a response for MX queries
+(define (parse-mx-response ans nss reply addr)
+  (let loop ([ans ans] [best-pref +inf.0] [exchanger #f])
+    (cond
+     [(null? ans)
+      (or (and exchanger (bytes->string/latin-1 exchanger))
+          ;; FIXME: Does 'soa mean that the input address is fine?
+          (and (ormap (lambda (ns) (eq? (rr-type ns) 'soa))
+                      nss)
+               addr))]
+     [else
+      (define type (rr-type (car ans)))
+      (define d (rr-data (car ans)))
+      (cond [(not (eq? type 'mx)) ; not MX record, keep going
+             (loop (cdr ans) best-pref exchanger)]
+            [else
+             (define pref (octet-pair->number (car d) (cadr d)))
+             (if (< pref best-pref)
+                 (let-values ([(name start) (parse-name (cddr d) reply)])
+                   (loop (cdr ans) pref name))
+                 (loop (cdr ans) best-pref exchanger))])])))
+
 (define (dns-find-nameserver)
   (case (system-type)
     [(unix macosx)
diff --git a/collects/tests/net/dns.rkt b/collects/tests/net/dns.rkt
index 336f6f032a..b34a8964f8 100644
--- a/collects/tests/net/dns.rkt
+++ b/collects/tests/net/dns.rkt
@@ -3,8 +3,66 @@
 (require net/dns tests/eli-tester)
 
 ;; internal tests
+
+(define mx-response-with-cname
+  '(;; random ID
+    0 187
+    ;; QR Opcode  AA TC RD RA Z     RCODE
+    ;; 1  0 0 0 0 0  0  1  1  0 0 0 0 0 0 0
+    129 128
+    ;; QDCOUNT
+    0 1
+    ;; ANSCOUNT
+    0 1
+    ;; NSCOUNT
+    0 1
+    ;; ARCOUNT
+    0 0
+    ;; QNAME (stat.ethz.ch)
+    4 115 116 97 116
+    4 101 116 104 122
+    2 99 104 0
+    ;; QTYPE (MX)
+    0 15
+    ;; QCLASS (IN)
+    0 1
+    ;; NAME (pointer)
+    ;; 1100000000001100
+    192 12
+    ;; TYPE: CNAME
+    0 5
+    ;; CLASS
+    0 1
+    ;; TTL
+    0 0
+    4 79
+    ;; RDLENGTH
+    0 19
+    ;; RDATA
+    11 109 97 103 101 108 108 97 110 45 48 54
+    4 109 97 116 104
+    192 17
+    ;; NAME (pointer)
+    192 17
+    ;; TYPE: SOA
+    0 6
+    ;; CLASS
+    0 1
+    ;; TTL
+    0 0 1 90
+    ;; RDLENGTH & DATA
+    0 44 8 100 117 109 109 121 45
+    110 115 192 17 10 104 111 115 116 109
+    97 115 116 101 114 192 17 119 168 176
+    33 0 0 42 48 0 0 14 16 0 27 175 128 0 0 2 88))
+
 (require (only-in rackunit require/expose) net/private/ip)
-(require/expose net/dns (ip->in-addr.arpa ip->ip6.arpa))
+(require/expose net/dns (ip->in-addr.arpa ip->ip6.arpa
+                         parse-reply parse-mx-response))
+
+(define-values (_1 _2 mx-ans mx-nss _3 _4)
+  (parse-reply '(0 187 129 128) mx-response-with-cname))
+
 (define (internal-tests)
   (test (ip->in-addr.arpa (ipv4 (bytes 8 8 8 8)))
         => "8.8.8.8.in-addr.arpa"
@@ -15,7 +73,11 @@
                           ".2.0.0.0.1.0.0.0.0.0.0.0.1.2.3.4.ip6.arpa")
         (ip->ip6.arpa (make-ip-address "2001:db8::567:89ab"))
         => (string-append "b.a.9.8.7.6.5.0.0.0.0.0.0.0.0.0"
-                          ".0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa")))
+                          ".0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa")
+        ;; FIXME: may need to change if SOA handling in net/dns
+        ;;        changes (see FIXME there)
+        (parse-mx-response mx-ans mx-nss mx-response-with-cname "stat.ethz.ch")
+        => "stat.ethz.ch"))
 
 ;; Constants for testing. These can go out of sync
 ;; when server setups change, so keep them up-to-date.