diff --git a/collects/tests/xrepl/known-module.rkt b/collects/tests/xrepl/known-module.rkt
new file mode 100644
index 0000000000..cb1aa718a7
--- /dev/null
+++ b/collects/tests/xrepl/known-module.rkt
@@ -0,0 +1,60 @@
+#lang racket/base
+
+(require xrepl/xrepl tests/eli-tester setup/dirs)
+
+(define known-module
+  (parameterize ([current-namespace (module->namespace 'xrepl/xrepl)])
+    (namespace-variable-value 'known-module)))
+
+(define-namespace-anchor a)
+(parameterize ([current-namespace (namespace-anchor->namespace a)])
+  (for-each eval '[(module top-module racket/base)
+                   (module mzlib/etc racket/base)]))
+
+(define etc-path     (collection-file-path "etc.rkt" "mzlib"))
+(define etc-pathstr  (path->string etc-path))
+(define base-path    (collection-file-path "base.rkt" "racket"))
+(define base-pathstr (path->string base-path))
+
+(provide test-known-module)
+(module+ main (test-known-module))
+(define (test-known-module)
+  (parameterize ([current-directory (find-collects-dir)])
+    (test
+     ;; normal mode
+     (known-module 'does-not-exist) => #f
+     (known-module ''top-module)  => ''top-module
+     (known-module 'top-module)   => ''top-module ; guesses the quoted name
+     (known-module ''#%kernel)    => ''#%kernel
+     (known-module '#%kernel)     => ''#%kernel   ; same here
+     (known-module 'racket/base)  => 'racket/base
+     (known-module ''racket/base) => #f ; the quoted name doesn't work
+     (known-module 'mzlib/etc)    => 'mzlib/etc ; symbol known, no guessing
+     (known-module ''mzlib/etc)   => ''mzlib/etc
+     (known-module "mzlib/etc.rkt") => "mzlib/etc.rkt"
+     (known-module `(file ,etc-pathstr)) => `(file ,etc-pathstr)
+     ;; path mode
+     (known-module 'does-not-exist 'path) => #f
+     (known-module ''top-module    'path) => #f
+     (known-module 'top-module     'path) => #f
+     (known-module ''#%kernel      'path) => #f
+     (known-module '#%kernel       'path) => #f
+     (known-module 'racket/base    'path) => base-path
+     (known-module ''racket/base   'path) => #f
+     (known-module 'mzlib/etc      'path) => etc-path
+     (known-module ''mzlib/etc     'path) => #f
+     (known-module "mzlib/etc.rkt" 'path) => etc-path
+     (known-module `(file ,etc-pathstr) 'path) => etc-path
+     ;; path/sym mode
+     (known-module 'does-not-exist 'path/sym) => #f
+     (known-module ''top-module    'path/sym) => 'top-module
+     (known-module 'top-module     'path/sym) => 'top-module
+     (known-module ''#%kernel      'path/sym) => '#%kernel
+     (known-module '#%kernel       'path/sym) => '#%kernel
+     (known-module 'racket/base    'path/sym) => base-path
+     (known-module ''racket/base   'path/sym) => #f
+     (known-module 'mzlib/etc      'path/sym) => etc-path
+     (known-module ''mzlib/etc     'path/sym) => 'mzlib/etc ; we have it too
+     (known-module "mzlib/etc.rkt" 'path/sym) => etc-path
+     (known-module `(file ,etc-pathstr) 'path/sym) => etc-path
+     )))