diff --git a/pkgs/racket-test-core/tests/racket/path.rktl b/pkgs/racket-test-core/tests/racket/path.rktl
index 50b3626eba..0ba7cd21b6 100644
--- a/pkgs/racket-test-core/tests/racket/path.rktl
+++ b/pkgs/racket-test-core/tests/racket/path.rktl
@@ -736,6 +736,7 @@
   (test (list (string->path "../aux/") (string->path "z")) get-base (coerce "../aux/z"))
   (test (list (string->path "../aux.m/") (string->path "z")) get-base (coerce "../aux.m/z"))
   (test (list (string->path "../") (string->path "\\\\?\\REL\\\\aux.m")) get-base (coerce "../aux.m/"))
+  (test (list (string->path "../") (string->path "auxy.m")) get-base (coerce "../auxy.m/"))
   (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux.m")) get-base (coerce "c:/aux.m/"))
   (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux.m.p")) get-base (coerce "c:/aux.m.p/"))
   (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux:m")) get-base (coerce "c:/aux:m/"))
diff --git a/racket/src/io/path/windows.rkt b/racket/src/io/path/windows.rkt
index 97284c6e79..ac29e63cbc 100644
--- a/racket/src/io/path/windows.rkt
+++ b/racket/src/io/path/windows.rkt
@@ -56,7 +56,7 @@
             (or (= len fn-len)
                 (eqv? (bytes-ref bstr fn-len) (char->integer #\.))
                 (eqv? (bytes-ref bstr fn-len) (char->integer #\:))
-                (for/and ([b (in-bytes bstr len)])
+                (for/and ([b (in-bytes bstr fn-len)])
                   (or (eqv? b (char->integer #\space))
                       (eqv? b (char->integer #\.)))))))]))