diff --git a/lib/Prelude.idr b/lib/Prelude.idr
index bf3750de8..cee70cf2a 100644
--- a/lib/Prelude.idr
+++ b/lib/Prelude.idr
@@ -24,10 +24,6 @@ import Prelude.Chars
 class Show a where 
     show : a -> String
 
-instance Show Nat where 
-    show O = "O"
-    show (S k) = "s" ++ show k
-
 instance Show Int where 
     show = prim__toStrInt
 
@@ -43,6 +39,9 @@ instance Show Char where
 instance Show String where 
     show = id
 
+instance Show Nat where 
+    show n = show (the Integer (cast n))
+
 instance Show Bool where 
     show True = "True"
     show False = "False"
diff --git a/test/reg004/expected b/test/reg004/expected
index 35bf93fe5..0d66ea1ae 100644
--- a/test/reg004/expected
+++ b/test/reg004/expected
@@ -1,2 +1,2 @@
-O
-sO
+0
+1
diff --git a/test/reg017/expected b/test/reg017/expected
index 7a53225be..b8626c4cf 100644
--- a/test/reg017/expected
+++ b/test/reg017/expected
@@ -1 +1 @@
-ssssO
+4
diff --git a/test/test005/expected b/test/test005/expected
index 390001daf..253ee757f 100644
--- a/test/test005/expected
+++ b/test/test005/expected
@@ -1,5 +1,5 @@
 8
-sO
+1
 (abc, 123)
 (abc, 123)
 ([1, 2], [3, 4, 5])
diff --git a/test/test007/expected b/test/test007/expected
index 59150d3e3..b18f26648 100644
--- a/test/test007/expected
+++ b/test/test007/expected
@@ -1,4 +1,4 @@
 Just 8
-Just sssssssssO
+Just 9
 Just 42
 Nothing
diff --git a/test/test019/expected b/test/test019/expected
index adc20b25b..d00491fd7 100644
--- a/test/test019/expected
+++ b/test/test019/expected
@@ -1 +1 @@
-sO
+1