diff --git a/scheme/ikarus.numerics.ss b/scheme/ikarus.numerics.ss
index 5d58316..8dea995 100644
--- a/scheme/ikarus.numerics.ss
+++ b/scheme/ikarus.numerics.ss
@@ -1268,7 +1268,7 @@
                          (quotient y g))))]))]
            [(flonum? y) ($fl/ (bignum->flonum x) y)]
            [(ratnum? y) 
-            (binary/ (binary* x ($ratnum-n y)) ($ratnum-d y))]
+            (binary/ (binary* x ($ratnum-d y)) ($ratnum-n y))]
            [(or (compnum? y) (cflonum? y)) (x/compy x y)]
            [else (err '/ y)])]
         [(ratnum? x)
diff --git a/scheme/last-revision b/scheme/last-revision
index a3845ee..e024c04 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1632
+1633
diff --git a/scheme/tests/div-and-mod.ss b/scheme/tests/div-and-mod.ss
index 33c481e..bdd51b8 100644
--- a/scheme/tests/div-and-mod.ss
+++ b/scheme/tests/div-and-mod.ss
@@ -4,9 +4,15 @@
   (import (ikarus))
 
   (define (run-tests)
+    (test-/)
     (test-div-and-mod)
     (test-div0-and-mod0))
 
+
+  (define (test-/)
+    (assert (= (/ 536870912 1/4) 2147483648)))
+
+
   (define (test-div-and-mod)
     (define (test x1 x2)
       (let-values ([(d m) (div-and-mod x1 x2)])