diff --git a/pkgs/racket-test-core/tests/racket/basic.rktl b/pkgs/racket-test-core/tests/racket/basic.rktl
index a10d85df01..1d631b5a00 100644
--- a/pkgs/racket-test-core/tests/racket/basic.rktl
+++ b/pkgs/racket-test-core/tests/racket/basic.rktl
@@ -293,11 +293,10 @@
 (test 'c list-ref '(a b c . d) 2)
 (arity-test list-ref 2 2)
 (err/rt-test (list-ref 1 1) exn:application:mismatch?)
-(err/rt-test (list-ref '(a b . c) 2) exn:application:mismatch?)
+(err/rt-test (list-ref '(a b . c) 2) exn:application:mismatch? #rx"index reaches a non-pair")
 (err/rt-test (list-ref '(1 2 3) 2.0))
 (err/rt-test (list-ref '(1) '(1)))
-(err/rt-test (list-ref '(1) 1) exn:application:mismatch?)
-(err/rt-test (list-ref '() 0) exn:application:mismatch?)
+(err/rt-test (list-ref '(1) 1) exn:application:mismatch? #rx"index too large for list")
 (err/rt-test (list-ref '() 0) exn:application:mismatch?)
 (err/rt-test (list-ref '(1) -1))
 (err/rt-test (list-ref '(1) 2000000000000) exn:application:mismatch?)
@@ -311,8 +310,8 @@
 (err/rt-test (list-tail '(1 2 3) 2.0))
 (err/rt-test (list-tail '(1) '(1)))
 (err/rt-test (list-tail '(1) -1))
-(err/rt-test (list-tail '(1) 2) exn:application:mismatch?)
-(err/rt-test (list-tail '(1 2 . 3) 3) exn:application:mismatch?)
+(err/rt-test (list-tail '(1) 2) exn:application:mismatch? #rx"index too large for list")
+(err/rt-test (list-tail '(1 2 . 3) 3) exn:application:mismatch? #rx"index reaches a non-pair")
 
 (err/rt-test (car 0) exn:fail:contract? #rx"car: contract violation.*expected: pair[?].*given: 0")
 (err/rt-test (cdr 0) exn:fail:contract? #rx"cdr: contract violation.*expected: pair[?].*given: 0")
diff --git a/racket/src/ChezScheme/mats/patch-compile-0-t-f-f b/racket/src/ChezScheme/mats/patch-compile-0-t-f-f
index 4a1b92c34b..36293883c2 100644
--- a/racket/src/ChezScheme/mats/patch-compile-0-t-f-f
+++ b/racket/src/ChezScheme/mats/patch-compile-0-t-f-f
@@ -171,8 +171,8 @@
   5_2.mo:Expected error in mat c....r-errors: "cddddr: incorrect list structure (a . b)".
 ! 5_2.mo:Expected error in mat list*: "incorrect argument count in call (list*)".
 ! 5_2.mo:Expected error in mat cons*: "incorrect argument count in call (cons*)".
-  5_2.mo:Expected error in mat list-ref: "list-ref: a is not a proper list".
-  5_2.mo:Expected error in mat list-ref: "list-ref: (a b . c) is not a proper list".
+  5_2.mo:Expected error in mat list-ref: "list-ref: index 0 reaches a non-pair in a".
+  5_2.mo:Expected error in mat list-ref: "list-ref: index 4 reaches a non-pair in (a b . c)".
   5_2.mo:Expected error in mat list-ref: "list-ref: index 4 is out of range for list (a b)".
 --- 693,700 ----
   5_2.mo:Expected error in mat c....r-errors: "cddadr: incorrect list structure (a . b)".
@@ -180,8 +180,8 @@
   5_2.mo:Expected error in mat c....r-errors: "cddddr: incorrect list structure (a . b)".
 ! 5_2.mo:Expected error in mat list*: "incorrect number of arguments -1 to #<procedure list*>".
 ! 5_2.mo:Expected error in mat cons*: "incorrect number of arguments -1 to #<procedure cons*>".
-  5_2.mo:Expected error in mat list-ref: "list-ref: a is not a proper list".
-  5_2.mo:Expected error in mat list-ref: "list-ref: (a b . c) is not a proper list".
+  5_2.mo:Expected error in mat list-ref: "list-ref: index 0 reaches a non-pair in a".
+  5_2.mo:Expected error in mat list-ref: "list-ref: index 4 reaches a non-pair in (a b . c)".
   5_2.mo:Expected error in mat list-ref: "list-ref: index 4 is out of range for list (a b)".
 ***************
 *** 781,793 ****
diff --git a/racket/src/ChezScheme/mats/root-experr-compile-0-f-f-f b/racket/src/ChezScheme/mats/root-experr-compile-0-f-f-f
index 16425c86d0..d4258cd9b4 100644
--- a/racket/src/ChezScheme/mats/root-experr-compile-0-f-f-f
+++ b/racket/src/ChezScheme/mats/root-experr-compile-0-f-f-f
@@ -695,46 +695,46 @@ primvars.mo:Expected error in mat trace-output-port: "trace-output-port: #<input
 5_2.mo:Expected error in mat c....r-errors: "cddddr: incorrect list structure (a . b)".
 5_2.mo:Expected error in mat list*: "incorrect argument count in call (list*)".
 5_2.mo:Expected error in mat cons*: "incorrect argument count in call (cons*)".
-5_2.mo:Expected error in mat list-ref: "list-ref: a is not a proper list".
-5_2.mo:Expected error in mat list-ref: "list-ref: (a b . c) is not a proper list".
+5_2.mo:Expected error in mat list-ref: "list-ref: index 0 reaches a non-pair in a".
+5_2.mo:Expected error in mat list-ref: "list-ref: index 4 reaches a non-pair in (a b . c)".
 5_2.mo:Expected error in mat list-ref: "list-ref: index 4 is out of range for list (a b)".
 5_2.mo:Expected error in mat list-ref: "list-ref: index 4 is out of range for list (a b c)".
 5_2.mo:Expected error in mat list-ref: "list-ref: index 4 is out of range for list (a b c d)".
-5_2.mo:Expected error in mat list-ref: "list-ref: (a b c . e) is not a proper list".
-5_2.mo:Expected error in mat list-ref: "list-ref: (a b c d . e) is not a proper list".
+5_2.mo:Expected error in mat list-ref: "list-ref: index 4 reaches a non-pair in (a b c . e)".
+5_2.mo:Expected error in mat list-ref: "list-ref: index 4 reaches a non-pair in (a b c d . e)".
 5_2.mo:Expected error in mat list-ref: "list-ref: index 5 is out of range for list (a b c d)".
 5_2.mo:Expected error in mat list-ref: "list-ref: index 5 is out of range for list (a b c d e)".
-5_2.mo:Expected error in mat list-ref: "list-ref: (a b c d e . f) is not a proper list".
-5_2.mo:Expected error in mat list-ref: "list-ref: (a b . c) is not a proper list".
+5_2.mo:Expected error in mat list-ref: "list-ref: index 5 reaches a non-pair in (a b c d e . f)".
+5_2.mo:Expected error in mat list-ref: "list-ref: index 10000 reaches a non-pair in (a b . c)".
 5_2.mo:Expected error in mat list-ref: "list-ref: index 10000 is out of range for list (a b c)".
-5_2.mo:Expected error in mat list-ref: "list-ref: (a b . c) is not a proper list".
+5_2.mo:Expected error in mat list-ref: "list-ref: index 444444444444444444444444444444444444444444 reaches a non-pair in (a b . c)".
 5_2.mo:Expected error in mat list-ref: "list-ref: index 444444444444444444444444444444444444444444 is out of range for list (a b c)".
 5_2.mo:Expected error in mat list-ref: "list-ref: index -1 is not an exact nonnegative integer".
 5_2.mo:Expected error in mat list-ref: "list-ref: index -4444444444444444444444 is not an exact nonnegative integer".
 5_2.mo:Expected error in mat list-ref: "list-ref: index a is not an exact nonnegative integer".
-5_2.mo:Expected error in mat list-tail: "list-tail: (a b . c) is not a proper list".
-5_2.mo:Expected error in mat list-tail: "list-tail: (a b c . d) is not a proper list".
-5_2.mo:Expected error in mat list-tail: "list-tail: (a b . c) is not a proper list".
-5_2.mo:Expected error in mat list-tail: "list-tail: (a b c . d) is not a proper list".
-5_2.mo:Expected error in mat list-tail: "list-tail: (a b c d . e) is not a proper list".
+5_2.mo:Expected error in mat list-tail: "list-tail: index 4 reaches a non-pair in (a b . c)".
+5_2.mo:Expected error in mat list-tail: "list-tail: index 4 reaches a non-pair in (a b c . d)".
+5_2.mo:Expected error in mat list-tail: "list-tail: index 5 reaches a non-pair in (a b . c)".
+5_2.mo:Expected error in mat list-tail: "list-tail: index 5 reaches a non-pair in (a b c . d)".
+5_2.mo:Expected error in mat list-tail: "list-tail: index 5 reaches a non-pair in (a b c d . e)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index 4 is out of range for list (a)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index 4 is out of range for list (a b)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index 4 is out of range for list (a b c)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index 5 is out of range for list (a b)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index 5 is out of range for list (a b c)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index 5 is out of range for list (a b c d)".
-5_2.mo:Expected error in mat list-tail: "list-tail: (a b . c) is not a proper list".
+5_2.mo:Expected error in mat list-tail: "list-tail: index 10000 reaches a non-pair in (a b . c)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index 10000 is out of range for list (a b c)".
-5_2.mo:Expected error in mat list-tail: "list-tail: (a b . c) is not a proper list".
+5_2.mo:Expected error in mat list-tail: "list-tail: index 444444444444444444444444444444444444444444 reaches a non-pair in (a b . c)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index 444444444444444444444444444444444444444444 is out of range for list (a b c)".
 5_2.mo:Expected error in mat list-tail: "list-tail: index -1 is not an exact nonnegative integer".
 5_2.mo:Expected error in mat list-tail: "list-tail: index -4444444444444444444444 is not an exact nonnegative integer".
 5_2.mo:Expected error in mat list-tail: "list-tail: index a is not an exact nonnegative integer".
-5_2.mo:Expected error in mat list-head: "list-head: (a . b) is not a proper list".
-5_2.mo:Expected error in mat list-head: "list-head: (a b . c) is not a proper list".
-5_2.mo:Expected error in mat list-head: "list-head: (a b . c) is not a proper list".
-5_2.mo:Expected error in mat list-head: "list-head: (a b c . d) is not a proper list".
-5_2.mo:Expected error in mat list-head: "list-head: (a b . c) is not a proper list".
+5_2.mo:Expected error in mat list-head: "list-head: index 3 reaches a non-pair in (a . b)".
+5_2.mo:Expected error in mat list-head: "list-head: index 3 reaches a non-pair in (a b . c)".
+5_2.mo:Expected error in mat list-head: "list-head: index 4 reaches a non-pair in (a b . c)".
+5_2.mo:Expected error in mat list-head: "list-head: index 4 reaches a non-pair in (a b c . d)".
+5_2.mo:Expected error in mat list-head: "list-head: index 10000 reaches a non-pair in (a b . c)".
 5_2.mo:Expected error in mat list-head: "list-head: index 4 is out of range for list (a b c)".
 5_2.mo:Expected error in mat list-head: "list-head: index 5 is out of range for list (a b c)".
 5_2.mo:Expected error in mat list-head: "list-head: index 5 is out of range for list (a b c d)".
diff --git a/racket/src/ChezScheme/s/5_2.ss b/racket/src/ChezScheme/s/5_2.ss
index 35ff456a39..f2d05cbd35 100644
--- a/racket/src/ChezScheme/s/5_2.ss
+++ b/racket/src/ChezScheme/s/5_2.ss
@@ -80,6 +80,9 @@
    (define index-range-error
       (lambda (who ls n)
          ($oops who "index ~s is out of range for list ~s" n ls)))
+   (define index-pair-error
+      (lambda (who ls n)
+         ($oops who "index ~s reaches a non-pair in ~s" n ls)))
    (define index-type-error
       (lambda (who n)
          ($oops who "index ~s is not an exact nonnegative integer" n)))
@@ -87,7 +90,7 @@
       (lambda (who tail ls n)
          (if (null? tail)
              (index-range-error who ls n)
-             (improper-list-error who ls))))
+             (index-pair-error who ls n))))
    (define list-length
      (lambda (ls who)
        (let loop ([hare ls] [i 0])
diff --git a/racket/src/cs/rumble/error-rewrite.ss b/racket/src/cs/rumble/error-rewrite.ss
index 0cd99c2a63..fd33d090d7 100644
--- a/racket/src/cs/rumble/error-rewrite.ss
+++ b/racket/src/cs/rumble/error-rewrite.ss
@@ -97,6 +97,18 @@
     => (lambda (ctc)
          (format-error-values (string-append "contract violation\n  expected: " ctc "\n  given: ~s")
                               irritants))]
+   [(and (or (eq? who 'list-ref) (eq? who 'list-tail))
+         (equal? str "index ~s is out of range for list ~s"))
+    (values (string-append "index too large for list\n"
+                           "  index: ~s\n"
+                           "  in: ~s")
+            irritants)]
+   [(and (or (eq? who 'list-ref) (eq? who 'list-tail))
+         (equal? str "index ~s reaches a non-pair in ~s"))
+    (values (string-append "index reaches a non-pair\n"
+                           "  index: ~s\n"
+                           "  in: ~s")
+            irritants)]
    [(equal? str  "~s is not a valid index for ~s")
     (cond
      [(exact-nonnegative-integer? (car irritants))