diff --git a/src/ikarus.boot b/src/ikarus.boot
index 63a3f3a..9718a34 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 28f722f..6f180cd 100644
--- a/src/ikarus.core.ss
+++ b/src/ikarus.core.ss
@@ -29,11 +29,6 @@
       (error 'char->integer "~s is not a character" x))
     ($char->fixnum x)))
   
-(primitive-set! 'fxlognot 
-  (lambda (x)
-    (unless (fixnum? x) 
-      (error 'fxlognot "~s is not a fixnum" x))
-    ($fxlognot x)))
   
 (let ()
   (define fill!
diff --git a/src/ikarus.fixnums.ss b/src/ikarus.fixnums.ss
index 69250cb..b20aa2a 100644
--- a/src/ikarus.fixnums.ss
+++ b/src/ikarus.fixnums.ss
@@ -1,9 +1,9 @@
 
 (library (ikarus fixnums)
-  (export fxzero? fxadd1 fxsub1)
+  (export fxzero? fxadd1 fxsub1 fxlognot)
   (import 
-    (only (scheme) $fxadd1 $fxsub1)
-    (except (ikarus) fxzero? fxadd1 fxsub1))
+    (only (scheme) $fxadd1 $fxsub1 $fxlognot)
+    (except (ikarus) fxzero? fxadd1 fxsub1 fxlognot))
 
   (define fxzero?
     (lambda (x)
@@ -24,4 +24,10 @@
           ($fxsub1 n)
           (error 'fxsub1 "~s is not a fixnum" n))))
 
+
+  (define fxlognot 
+    (lambda (x)
+      (unless (fixnum? x) 
+        (error 'fxlognot "~s is not a fixnum" x))
+      ($fxlognot x)))
   )