diff --git a/collects/swindle/readme.txt b/collects/swindle/readme.txt
index 205413c95b..201eb6b6d6 100644
--- a/collects/swindle/readme.txt
+++ b/collects/swindle/readme.txt
@@ -152,6 +152,6 @@ Copyright (C) 1998-2007 Eli Barzilay (eli@barzilay.org)
     You should have received a copy of the GNU Lesser General Public
     License along with this library; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-    02110-1301 USA
+    02110-1301 USA.
 
 ====< * >===============================================================
diff --git a/collects/swindle/tiny-clos.ss b/collects/swindle/tiny-clos.ss
index d3342b915e..f23e1ef5d8 100644
--- a/collects/swindle/tiny-clos.ss
+++ b/collects/swindle/tiny-clos.ss
@@ -496,17 +496,20 @@
 (define* (struct-type->class stype)
   (hash-table-get
    struct-to-class-table stype
-   (thunk (let-values ([(name init-field-k auto-field-k accessor mutator
-                         immutable-k-list super skipped?)
-                        (struct-type-info stype)])
-            (let* ([super (cond [super (struct-type->class super)]
-                                [skipped? <opaque-struct>]
-                                [else <struct>])]
-                   [this (parameterize ([*default-object-class* #f])
-                           (make <primitive-class>
-                                 :name name :direct-supers (list super)))])
-              (hash-table-put! struct-to-class-table stype this)
-              this)))))
+   (thunk
+     (let-values ([(name init-field-k auto-field-k accessor mutator
+                    immutable-k-list super skipped?)
+                   (struct-type-info stype)])
+       (let* ([supers (list (cond [super (struct-type->class super)]
+                                  [skipped? <opaque-struct>]
+                                  [else <struct>]))]
+              [proc? (procedure-struct-type? stype)]
+              [supers (if proc? (cons <primitive-procedure> supers) supers)]
+              [this (parameterize ([*default-object-class* #f])
+                      (make (if proc? <procedure-class> <primitive-class>)
+                            :name name :direct-supers (list super)))])
+         (hash-table-put! struct-to-class-table stype this)
+         this)))))
 
 ;;>>...
 ;;> *** Common accessors