diff --git a/collects/lang/htdp-langs.ss b/collects/lang/htdp-langs.ss
index ccdfd56f1d..0cd769aa91 100644
--- a/collects/lang/htdp-langs.ss
+++ b/collects/lang/htdp-langs.ss
@@ -33,7 +33,8 @@
            ;; and the user's namespace in the teaching languages
            "private/set-result.ss"
            
-           (lib "stepper-language-interface.ss" "stepper"))
+           (lib "stepper-language-interface.ss" "stepper")
+           (lib "debugger-language-interface.ss" "mztake"))
   
   (provide tool@)
   
@@ -873,18 +874,26 @@
         
         (send dlg show #t)
         answer)
-      
+
       (define (stepper-settings-language %)
-        (class* % (stepper-language<%>)
-	  (init-field stepper:supported)
-          (init-field stepper:enable-let-lifting)
-          (inherit [dontcare1 stepper:enable-let-lifting?]
-		   [dontcare2 stepper:supported?]
-		   [dontcare3 debugger:supported?])
-          (define/override (stepper:supported?) stepper:supported)
-          (define/override (stepper:enable-let-lifting?) stepper:enable-let-lifting)
-	  (define/override (debugger:supported?) #f)
-          (super-new)))
+        (if (implementation? % stepper-language<%>)
+            (class* % (stepper-language<%>)
+              (init-field stepper:supported)
+              (init-field stepper:enable-let-lifting)
+              (define/override (stepper:supported?) stepper:supported)
+              (define/override (stepper:enable-let-lifting?) stepper:enable-let-lifting)
+              (super-new))
+            (class* % ()
+              (init stepper:supported)
+              (init stepper:enable-let-lifting)
+              (super-new))))
+
+      (define (debugger-settings-language %)
+        (if (implementation? % debugger-language<%>)
+            (class* % (debugger-language<%>)
+              (define/override (debugger:supported?) #f)
+              (super-new))
+            %))
 
       ;; rewrite-module : settings syntax -> syntax
       ;; rewrites te module to print out results of non-definitions
@@ -1358,12 +1367,13 @@
       (define (phase2)
         (define htdp-language%
           (stepper-settings-language
-           ((drscheme:language:get-default-mixin)
-            (language-extension
-             (drscheme:language:module-based-language->language-mixin
-              (module-based-language-extension
-               (drscheme:language:simple-module-based-language->module-based-language-mixin
-                simple-htdp-language%)))))))
+           (debugger-settings-language
+            ((drscheme:language:get-default-mixin)
+             (language-extension
+              (drscheme:language:module-based-language->language-mixin
+               (module-based-language-extension
+                (drscheme:language:simple-module-based-language->module-based-language-mixin
+                 simple-htdp-language%))))))))
         
         (add-htdp-language
          (instantiate htdp-language% ()
diff --git a/collects/mztake/debug-tool.ss b/collects/mztake/debug-tool.ss
index 07febfe0d4..7ce18f0700 100644
--- a/collects/mztake/debug-tool.ss
+++ b/collects/mztake/debug-tool.ss
@@ -17,7 +17,7 @@
            "load-sandbox.ss"
            (lib "framework.ss" "framework")
            (lib "string-constant.ss" "string-constants")
-           )
+           "debugger-language-interface.ss")
   
   (provide tool@)
   
@@ -30,9 +30,6 @@
       (import drscheme:tool^)
       (export drscheme:tool-exports^) 
 
-      (define debugger-language<%>
-	(interface () debugger:supported?))
-
       (define (phase1)
 	(drscheme:language:extend-language-interface
          debugger-language<%>
diff --git a/collects/mztake/debugger-language-interface.ss b/collects/mztake/debugger-language-interface.ss
new file mode 100644
index 0000000000..e3d9776fbb
--- /dev/null
+++ b/collects/mztake/debugger-language-interface.ss
@@ -0,0 +1,9 @@
+
+(module debugger-language-interface mzscheme
+  (require (lib "class.ss"))
+  (provide debugger-language<%>)
+
+  (define debugger-language<%>
+    (interface () debugger:supported?)))
+
+  
\ No newline at end of file