diff --git a/pkgs/racket-test-core/tests/racket/object.rktl b/pkgs/racket-test-core/tests/racket/object.rktl
index 8c75161bd6..cceb878186 100644
--- a/pkgs/racket-test-core/tests/racket/object.rktl
+++ b/pkgs/racket-test-core/tests/racket/object.rktl
@@ -1235,6 +1235,40 @@
 	      (super-new)))])
   (test 16 'send-using-local (send (new c%) pub 3)))
 
+;; Make sure local names are checked correctly for deciding
+;; conflicting method names:
+(let ()
+  (define-syntax-rule (defclss name% x y)
+    (begin
+      (define-local-member-name f)
+      (define name%
+        (class object%
+          (super-new)
+          (define/public (f) 5)
+          (define/public (x) 6)
+          (define/public (y) 7)))
+      (test 5 'local-f (send (new name%) f))))
+
+  (defclss one% f y)
+  (test 6 'normal-f (send (new one%) f))
+  (test 7 'normal-y (send (new one%) y))
+  
+  (define-syntax-rule (defclss2 name% x)
+    (begin
+      (define-local-member-name f)
+      (defclss name% f x)
+      (test 6 'middle-f (send (new name%) f))))
+
+  (defclss2 two% f)
+  (test 7 'normal-f (send (new two%) f)))
+
+(syntax-test #'(let ()
+                 (define-local-member-name f)
+                 (class object%
+                   (super-new)
+                   (define/public (f) 5)
+                   (define/public (f) 6))))
+
 ;; ------------------------------------------------------------
 ;; `send+' tests
 
diff --git a/racket/collects/racket/private/class-internal.rkt b/racket/collects/racket/private/class-internal.rkt
index 881fa42f6e..9449402a53 100644
--- a/racket/collects/racket/private/class-internal.rkt
+++ b/racket/collects/racket/private/class-internal.rkt
@@ -1137,9 +1137,15 @@
                            (lambda (what l)
                              (let ([ht (make-hasheq)])
                                (for-each (lambda (id)
-                                           (when (hash-ref ht (syntax-e id) #f)
+                                           (define key (let ([l-id (lookup-localize id)])
+                                                         (if (identifier? l-id)
+                                                             (syntax-e l-id)
+                                                             ;; For a given localized id, `lookup-localize`
+                                                             ;; will return the same (eq?) value
+                                                             l-id)))
+                                           (when (hash-ref ht key #f)
                                              (bad (format "duplicate declared external ~a name" what) id))
-                                           (hash-set! ht (syntax-e id) #t))
+                                           (hash-set! ht key #t))
                                          l)))])
                       ;; method names
                       (check-dup "method" (map cdr (append publics overrides augrides