diff --git a/pkgs/racket-pkgs/racket-doc/pkg/scribblings/pkg.scrbl b/pkgs/racket-pkgs/racket-doc/pkg/scribblings/pkg.scrbl
index 306f78254f..59509c0924 100644
--- a/pkgs/racket-pkgs/racket-doc/pkg/scribblings/pkg.scrbl
+++ b/pkgs/racket-pkgs/racket-doc/pkg/scribblings/pkg.scrbl
@@ -4,7 +4,8 @@
           "common.rkt"
           (for-label pkg
                      (except-in racket/base remove)
-                     setup/dirs))
+                     setup/dirs
+                     setup/matching-platform))
 
 @(define @|Planet1| @|PLaneT|)
 
@@ -813,7 +814,8 @@ The following @filepath{info.rkt} fields are used by the package manager:
                @racket[(system-type)] when @racket[_platforms-spec] is
                a symbol or @racket[(path->string
                (system-library-subpath #f))] when
-               @racket[_platform-spec] is a regular expression.  For
+               @racket[_platform-spec] is a string or regular expression.
+               See also @racket[matching-platform?]. For
                example, platform-specific binaries can be placed into
                their own packages, with one separate package and one
                dependency for each supported platform.}
diff --git a/pkgs/racket-pkgs/racket-doc/scribblings/raco/setup.scrbl b/pkgs/racket-pkgs/racket-doc/scribblings/raco/setup.scrbl
index ae910b9481..1b3c2cd672 100644
--- a/pkgs/racket-pkgs/racket-doc/scribblings/raco/setup.scrbl
+++ b/pkgs/racket-pkgs/racket-doc/scribblings/raco/setup.scrbl
@@ -12,6 +12,7 @@
                     setup/getinfo
                     setup/main-collects
                     setup/collection-name
+                    setup/matching-platform
                     setup/path-to-relative
                     setup/xref scribble/xref
                     ;; info -- no bindings from this are used
@@ -599,18 +600,13 @@ Optional @filepath{info.rkt} fields trigger additional actions by
    @racket[copy-man-pages], but the original file is removed after it
    is copied (which makes sense for precompiled packages).}
 
- @item{@indexed-racket[install-platform] : @racket[(or/c regexp?
-   string? symbol?)] --- Determines whether files are copied or moved
+ @item{@indexed-racket[install-platform] : @racket[platform-spec?]
+   --- Determines whether files are copied or moved
    for @racket[copy-foreign-libs], @racket[move-foreign-libs],
-   @racket[copy-shared-files], or @racket[move-shared-files]. If
-   @racket[install-platform] is defined as a regexp, then files are
-   copied/moved only if the regexp matches the result of
-   @racket[(system-library-subpath #f)]. If @racket[install-platform]
-   is defined as a string, then files are copied/moved only if the
-   @racket[(path->string (system-library-subpath #f))] produces the
-   same string. If @racket[install-platform] is defined as a symbol,
-   then files are copied/moved only if the @racket[(system-type)]
-   produces the same symbol.}
+   @racket[copy-shared-files], or @racket[move-shared-files]. 
+   See @racket[matching-platform?] for information on the way that the
+   specification is compared to @racket[(system-type)]
+   and @racket[(system-library-subpath #f)].}
 
  @item{@indexed-racket[install-collection] : @racket[path-string?]  --- A
    library module relative to the collection that provides
@@ -1518,6 +1514,41 @@ is not the ASCII value of a letter, digit, @litchar{-}, @litchar{+},
 or @litchar{_}.}
 
 
+
+@; ------------------------------------------------------------------------
+
+@section[#:tag "matching-platform"]{API for Platform Specifications}
+
+@defmodule[setup/matching-platform]
+
+@history[#:added "6.0.1.13"]
+
+@defproc[(platform-spec? [v any/c]) boolean?]{
+
+Returns @racket[#t] if @racket[v] is a symbol, string, or regexp value
+(in the sense of @racket[regexp?]), @racket[#f] otherwise.}
+
+@defproc[(matching-platform? [spec platform-spec?]
+                             [#:system-type sys-type (or/c #f symbol?) (system-type)]
+                             [#:system-library-subpath sys-lib-subpath (or/c #f path?)
+                                                       (system-library-subpath #f)])
+         boolean?]{
+
+Reports whether @racket[spec] matches @racket[sys-type] or
+@racket[sys-lib-subpath], where @racket[#f] values for the latter are
+replaced with the default values.
+
+If @racket[spec] is a symbol, then the result is @racket[#t] if
+@racket[sys-type] is the same symbol, @racket[#f] otherwise.
+
+If @racket[spec] is a string, then the result is @racket[#t] if
+@racket[(path->string sys-lib-subpath)] is the same string,
+@racket[#f] otherwise.
+
+If @racket[spec] is a regexp value, then the result is @racket[#t] if
+the regexp matches @racket[(path->string sys-lib-subpath)],
+@racket[#f] otherwise.}
+
 @; ------------------------------------------------------------------------
 
 @section[#:tag "xref"]{API for Cross-References for Installed Manuals}
diff --git a/pkgs/racket-pkgs/racket-test/tests/setup/matching-platform.rkt b/pkgs/racket-pkgs/racket-test/tests/setup/matching-platform.rkt
new file mode 100644
index 0000000000..b9ea70e847
--- /dev/null
+++ b/pkgs/racket-pkgs/racket-test/tests/setup/matching-platform.rkt
@@ -0,0 +1,25 @@
+#lang racket/base
+(require setup/matching-platform
+         rackunit
+         racket/string)
+
+(check-equal? #t (platform-spec? (system-type)))
+(check-equal? #t (platform-spec? "string"))
+(check-equal? #t (platform-spec? #rx"regexp"))
+(check-equal? #f (platform-spec? #"bytes"))
+(check-equal? #f (platform-spec? 11))
+
+(check-equal? #t (matching-platform? (system-type)))
+(check-equal? #f (matching-platform? 'no-such-system-type))
+(check-equal? #t (matching-platform? 'unix #:system-type 'unix))
+(check-equal? #t (matching-platform? 'windows #:system-type 'windows))
+
+(check-equal? #t (matching-platform? (path->string (system-library-subpath #f))))
+(check-equal? #f (matching-platform? "no-such-platform"))
+(check-equal? #t (matching-platform? "no-such-platform" #:system-library-subpath (build-path "no-such-platform")))
+(check-equal? #f (matching-platform? "no" #:system-library-subpath (build-path "no-such-platform")))
+
+(check-equal? #t (matching-platform? #rx"."))
+(check-equal? #t (matching-platform? (regexp-quote (path->string (system-library-subpath #f)))))
+(check-equal? #f (matching-platform? #rx"^no-such-platform$"))
+(check-equal? #t (matching-platform? #rx"^no-such-platform$" #:system-library-subpath (build-path "no-such-platform")))
diff --git a/racket/collects/pkg/lib.rkt b/racket/collects/pkg/lib.rkt
index fc50e84801..56ede4be41 100644
--- a/racket/collects/pkg/lib.rkt
+++ b/racket/collects/pkg/lib.rkt
@@ -11,6 +11,7 @@
          setup/unpack
          setup/dirs
          setup/collection-name
+         setup/matching-platform
          racket/port
          racket/list
          racket/function
@@ -336,14 +337,7 @@
 
 (define (dependency-this-platform? dep)
   (define p (dependency-lookup '#:platform dep))
-  (if p
-      (if (symbol? p)
-          (eq? p (system-type))
-          (let ([s (path->string (system-library-subpath #f))])
-            (if (regexp? p)
-                (regexp-match? p s)
-                (equal? p s))))
-      #t))
+  (or (not p) (matching-platform? p)))
 
 (define pkg-lock-held (make-parameter #f))
 (define pkg-lock-scope (make-parameter #f))
diff --git a/racket/collects/setup/matching-platform.rkt b/racket/collects/setup/matching-platform.rkt
new file mode 100644
index 0000000000..9e89e022b2
--- /dev/null
+++ b/racket/collects/setup/matching-platform.rkt
@@ -0,0 +1,28 @@
+#lang racket/base
+
+(provide platform-spec?
+         matching-platform?)
+
+(define (platform-spec? p)
+  (or (symbol? p) (string? p) (regexp? p)))
+
+(define (matching-platform? p
+                            #:system-type [sys-type #f]
+                            #:system-library-subpath [sys-lib-subpath #f])
+  (unless (platform-spec? p)
+    (raise-argument-error 'matching-platform? "platform-spec?" p))
+  (unless (or (not sys-type) (symbol? sys-type))
+    (raise-argument-error 'matching-platform? "(or/c symbol? #f)" sys-type))
+  (unless (or (not sys-lib-subpath) (path? sys-lib-subpath))
+    (raise-argument-error 'matching-platform? "(or/c path? #f)" sys-lib-subpath))
+  (cond
+   [(symbol? p)
+    (eq? p (or sys-type (system-type)))]
+   [else
+    (define s (path->string (or sys-lib-subpath
+                                (system-library-subpath #f))))
+    (cond
+     [(regexp? p)
+      (regexp-match? p s)]
+     [else
+      (equal? p s)])]))
diff --git a/racket/collects/setup/setup-core.rkt b/racket/collects/setup/setup-core.rkt
index ac8eaf9577..adbdb7ebe4 100644
--- a/racket/collects/setup/setup-core.rkt
+++ b/racket/collects/setup/setup-core.rkt
@@ -25,6 +25,7 @@
          "unpack.rkt"
          "getinfo.rkt"
          "dirs.rkt"
+         "matching-platform.rkt"
          "main-collects.rkt"
          "path-to-relative.rkt"
          "path-relativize.rkt"
@@ -838,10 +839,7 @@
                                (string? v)
                                (symbol? v))
                      (error "entry is not regexp, string, or symbol:" v)))))
-    (cond
-     [(regexp? sys) (regexp-match? sys (system-library-subpath #f))]
-     [(symbol? sys) (eq? sys (system-type))]
-     [else (equal? sys (path->string (system-library-subpath #f)))]))
+    (matching-platform? sys))
 
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;                  Make zo                      ;;