diff --git a/src/ikarus.boot b/src/ikarus.boot
index eec14c8..6f5e231 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.io.output-strings.ss b/src/ikarus.io.output-strings.ss
index 151afbe..891e77f 100644
--- a/src/ikarus.io.output-strings.ss
+++ b/src/ikarus.io.output-strings.ss
@@ -33,10 +33,6 @@
             (match-and-bind targs (msg-arg* ...) (begin b b* ...))] ...
            [else else1 else2 ...]))]))
   
-  (define string-copy 
-    (lambda (s)
-      (substring s 0 (string-length s))))
-
   (define concat-old
     (lambda (str i ls)
       (let ([n (sum i ls)])
diff --git a/src/ikarus.strings.ss b/src/ikarus.strings.ss
index 8930769..a810f4f 100644
--- a/src/ikarus.strings.ss
+++ b/src/ikarus.strings.ss
@@ -1,7 +1,8 @@
 
 (library (ikarus strings)
   (export string-length string-ref string-set! make-string string->list string=?
-          string-append substring string list->string uuid)
+          string-append substring string list->string uuid
+          string-copy)
   (import 
     (ikarus system $strings)
     (ikarus system $fx)
@@ -10,7 +11,7 @@
     (ikarus system $pairs)
     (except (ikarus) string-length string-ref string-set! make-string
             string->list string=? string-append substring string
-            list->string uuid))
+            list->string uuid string-copy))
 
 
   (define string-length
@@ -117,6 +118,12 @@
                  ""
                  (fill s ($make-string len) n m 0)))))))
 
+  (define string-copy 
+    (lambda (s)
+      (if (string? s)
+          (substring s 0 (string-length s))
+          (error 'string-copy "~s is not a string" s))))
+  
   (module (string=?)
     (define bstring=?
       (lambda (s1 s2 i j)
diff --git a/src/makefile.ss b/src/makefile.ss
index 3aa92bb..8921525 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -235,9 +235,9 @@
     [and               i r]
     [or                i r]
     [...               i r]
-    [=>               i r]
-    [else               i r]
-    [_               i r]
+    [=>                i r]
+    [else              i r]
+    [_                 i r]
     ))
 
 (define ikarus-procedures-map
@@ -331,6 +331,7 @@
     [string=?                i r]
     [string-ci=?             i unicode]
     [substring               i r]
+    [string-copy             i r]
     [string-append           i r]
     [string->list            i r]
     [list->string            i r]
diff --git a/src/todo-r6rs.ss b/src/todo-r6rs.ss
index 78e59c1..dea2397 100755
--- a/src/todo-r6rs.ss
+++ b/src/todo-r6rs.ss
@@ -203,7 +203,7 @@
     [string->number                             C ba]
     [string->symbol                             C ba]
     [string-append                              C ba]
-    [string-copy                                S ba]
+    [string-copy                                C ba]
     [string-for-each                            S ba]
     [string-length                              C ba]
     [string-ref                                 C ba]
@@ -231,9 +231,9 @@
     [vector?                                    C ba]
     [zero?                                      C ba]
     [...                                        C ba sc]
-    [=>                                         S ba ex]
-    [_                                          S ba sc]
-    [else                                       S ba ex]
+    [=>                                         C ba ex]
+    [_                                          C ba sc]
+    [else                                       C ba ex]
 
     [bitwise-and                                D bw]
     [bitwise-arithmetic-shift                   D bw]