diff --git a/src/ikarus.boot b/src/ikarus.boot
index 9634267..2a7e5e7 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.core.ss b/src/ikarus.core.ss
index cf05581..28f722f 100644
--- a/src/ikarus.core.ss
+++ b/src/ikarus.core.ss
@@ -12,18 +12,7 @@
   (lambda () (void)))
   
 
-(primitive-set! 'fxadd1
-  (lambda (n)
-    (if (fixnum? n)
-        ($fxadd1 n)
-        (error 'fxadd1 "~s is not a fixnum" n))))
-  
-(primitive-set! 'fxsub1 
-  (lambda (n) 
-    (if (fixnum? n)
-        ($fxsub1 n)
-        (error 'fxsub1 "~s is not a fixnum" n))))
-  
+ 
 
 (primitive-set! 'integer->char
   (lambda (n)
diff --git a/src/ikarus.numerics.ss b/src/ikarus.numerics.ss
index 6a4d91e..562280d 100644
--- a/src/ikarus.numerics.ss
+++ b/src/ikarus.numerics.ss
@@ -3,16 +3,31 @@
 
 
 (library (ikarus fixnums)
-  (export fxzero?)
+  (export fxzero? fxadd1 fxsub1)
   (import 
-    (except (ikarus) fxzero?))
+    (only (scheme) $fxadd1 $fxsub1)
+    (except (ikarus) fxzero? fxadd1 fxsub1))
 
   (define fxzero?
     (lambda (x)
       (cond
         [(eq? x 0) #t]
         [(fixnum? x) #f]
-        [else (error 'fxzero? "~s is not a fixnum" x)]))))
+        [else (error 'fxzero? "~s is not a fixnum" x)])))
+  
+  (define fxadd1
+    (lambda (n)
+      (if (fixnum? n)
+          ($fxadd1 n)
+          (error 'fxadd1 "~s is not a fixnum" n))))
+  
+  (define fxsub1 
+    (lambda (n) 
+      (if (fixnum? n)
+          ($fxsub1 n)
+          (error 'fxsub1 "~s is not a fixnum" n))))
+
+  )
 
 
 (library (ikarus flonums)