diff --git a/collects/stepper/external-interface.rkt b/collects/stepper/external-interface.rkt
index c2eb5c6b26..5136fae263 100644
--- a/collects/stepper/external-interface.rkt
+++ b/collects/stepper/external-interface.rkt
@@ -1,6 +1,7 @@
-#lang racket
+#lang racket/base
 
-(require "private/annotate.rkt"
+(require racket/contract
+         "private/annotate.rkt"
          "private/marks.rkt")
 
 ;; an external interface for the stepper.
diff --git a/collects/stepper/private/annotate.rkt b/collects/stepper/private/annotate.rkt
index ece889520d..239c1a0e92 100644
--- a/collects/stepper/private/annotate.rkt
+++ b/collects/stepper/private/annotate.rkt
@@ -1,6 +1,7 @@
-#lang racket
+#lang racket/base
 
 (require (prefix-in kernel: syntax/kerncase)
+         racket/match
          racket/contract
          "marks.rkt"
          "shared.rkt"
diff --git a/collects/stepper/private/display-break-stuff.rkt b/collects/stepper/private/display-break-stuff.rkt
index 8942841922..3eaae39bbb 100644
--- a/collects/stepper/private/display-break-stuff.rkt
+++ b/collects/stepper/private/display-break-stuff.rkt
@@ -1,6 +1,6 @@
-#lang racket
+#lang racket/base
 
-(require mred mzlib/class "marks.rkt")
+(require racket/gui racket/class "marks.rkt")
 
 (provide display-break-stuff)
 
@@ -63,5 +63,3 @@
                              returned-value-list)
   (add-sel break-number mark-set break-kind returned-value-list)
   (send f show #t))
-  
-  
diff --git a/collects/stepper/private/lifting.rkt b/collects/stepper/private/lifting.rkt
index 466df5d1d5..1d05d85a51 100644
--- a/collects/stepper/private/lifting.rkt
+++ b/collects/stepper/private/lifting.rkt
@@ -1,6 +1,8 @@
-#lang racket
+#lang racket/base
 
 (require (prefix-in kernel: syntax/kerncase)
+         racket/match
+         racket/contract
          "shared.rkt"
          "syntax-property.rkt"
          (for-syntax racket/base))
diff --git a/collects/stepper/private/macro-unwind.rkt b/collects/stepper/private/macro-unwind.rkt
index e221af4094..8616b48548 100644
--- a/collects/stepper/private/macro-unwind.rkt
+++ b/collects/stepper/private/macro-unwind.rkt
@@ -1,6 +1,8 @@
-#lang racket
+#lang racket/base
 
 (require (only-in syntax/kerncase kernel-syntax-case)
+         racket/list
+         racket/contract
          "model-settings.rkt"
          "shared.rkt"
          "syntax-property.rkt")
diff --git a/collects/stepper/private/mred-extensions.rkt b/collects/stepper/private/mred-extensions.rkt
index 6cc0e93df7..c3e7598de8 100644
--- a/collects/stepper/private/mred-extensions.rkt
+++ b/collects/stepper/private/mred-extensions.rkt
@@ -1,6 +1,6 @@
-#lang racket
- 
-(require mred
+#lang racket/base
+
+(require racket/gui
          (prefix-in f: framework)
          racket/pretty
          "syntax-property.rkt"
diff --git a/collects/stepper/private/my-macros.rkt b/collects/stepper/private/my-macros.rkt
index ee610095f8..2030750415 100644
--- a/collects/stepper/private/my-macros.rkt
+++ b/collects/stepper/private/my-macros.rkt
@@ -1,5 +1,7 @@
-#lang racket
+#lang racket/base
 
+(require (for-syntax racket/base)
+         racket/match)
 
 ;;;;;;;;;;
 ;;
diff --git a/collects/stepper/private/shared.rkt b/collects/stepper/private/shared.rkt
index e11c39080f..f45ef24e4b 100644
--- a/collects/stepper/private/shared.rkt
+++ b/collects/stepper/private/shared.rkt
@@ -1,6 +1,11 @@
-#lang racket
+#lang racket/base
 
-(require "syntax-property.rkt")
+(require racket/list
+         racket/match
+         racket/contract
+         racket/class
+         racket/unit
+         "syntax-property.rkt")
 
 ; CONTRACTS
 
diff --git a/collects/stepper/private/xml-snip-helpers.rkt b/collects/stepper/private/xml-snip-helpers.rkt
index 33b7804860..d9fc7d2423 100644
--- a/collects/stepper/private/xml-snip-helpers.rkt
+++ b/collects/stepper/private/xml-snip-helpers.rkt
@@ -1,8 +1,8 @@
-#lang racket
+#lang racket/base
 
 (require xml/xml
          syntax/readerr
-         mred
+         racket/gui
          "syntax-property.rkt")
 
 (provide xml-read-special
diff --git a/collects/stepper/stepper+xml-tool.rkt b/collects/stepper/stepper+xml-tool.rkt
index f3e05e45d5..7dd8cb52f1 100644
--- a/collects/stepper/stepper+xml-tool.rkt
+++ b/collects/stepper/stepper+xml-tool.rkt
@@ -1,6 +1,7 @@
-#lang racket
+#lang racket/base
 
-(require drracket/tool
+(require racket/unit
+         drracket/tool
          "stepper-tool.rkt"
          "xml-tool.rkt"
          "private/view-controller.rkt")
diff --git a/collects/stepper/xml-tool.rkt b/collects/stepper/xml-tool.rkt
index f3c64d6206..5f3739dbd9 100644
--- a/collects/stepper/xml-tool.rkt
+++ b/collects/stepper/xml-tool.rkt
@@ -1,9 +1,10 @@
-#lang racket
+#lang racket/base
 
 (require "private/xml-snip-helpers.rkt"
          "private/find-tag.rkt"
          "private/xml-sig.rkt"
-         mred
+         racket/unit
+         racket/gui
          framework
          drracket/tool
          xml/xml