diff --git a/collects/typed-scheme/typecheck/tc-app-helper.ss b/collects/typed-scheme/typecheck/tc-app-helper.ss
index e228c754..220b26f8 100644
--- a/collects/typed-scheme/typecheck/tc-app-helper.ss
+++ b/collects/typed-scheme/typecheck/tc-app-helper.ss
@@ -19,31 +19,42 @@
            (format "~a~a *~a" doms-string rst rng-string)]
           [else (string-append (stringify (map make-printable dom)) rng-string)])))
 
-(define (domain-mismatches ty doms rests drests rngs arg-tys tail-ty tail-bound #:expected [expected #f])
+(define (domain-mismatches ty doms rests drests rngs arg-tys tail-ty tail-bound
+                           #:expected [expected #f])
   (define arguments-str
-    (stringify-domain arg-tys (if (not tail-bound) tail-ty #f) (if tail-bound (cons tail-ty tail-bound) #f)))    
+    (stringify-domain arg-tys
+                      (if (not tail-bound) tail-ty #f)
+                      (if tail-bound (cons tail-ty tail-bound) #f)))
   (cond
     [(null? doms)
      (int-err "How could doms be null: ~a ~a" ty)]
     [(= 1 (length doms))
-     (format "Domain: ~a~nArguments: ~a~n~a"
-             (stringify-domain (car doms) (car rests) (car drests))
-             arguments-str
-             (if expected
-                 (format "Result type: ~a~nExpected result: ~a~n"
-                         (car rngs) (make-printable expected))
-                 ""))]
+     (string-append
+      "Domain: "
+      (stringify-domain (car doms) (car rests) (car drests))
+      "\nArguments: "
+      arguments-str
+      "\n"
+      (if expected
+        (format "Result type: ~a\nExpected result: ~a\n"
+                (car rngs) (make-printable expected))
+        ""))]
     [else
-     (format "~a: ~a~nArguments: ~a~n~a"
-             (if expected "Types" "Domains")
-             (stringify (if expected 
-                            (map stringify-domain (map make-printable doms) rests drests rngs)
-                            (map stringify-domain (map make-printable doms) rests drests))
-                        "~n\t")
-             arguments-str
-             (if expected
-                 (format "Expected result: ~a~n" (make-printable expected))
-                 ""))]))
+     (let ([label  (if expected   "Types: "   "Domains: ")]
+           [nl+spc (if expected "\n       " "\n         ")]
+           [pdoms  (map make-printable doms)])
+       (string-append
+        label
+        (stringify (if expected
+                     (map stringify-domain pdoms rests drests rngs)
+                     (map stringify-domain pdoms rests drests))
+                   nl+spc)
+        "\nArguments: "
+        arguments-str
+        "\n"
+        (if expected
+          (format "Expected result: ~a\n" (make-printable expected))
+          "")))]))
 
 (define (poly-fail t argtypes #:name [name #f] #:expected [expected #f])
   (match t