2 files changed, 10 insertions, 13 deletions
diff --git a/stdlib/source/lux/math.lux b/stdlib/source/lux/math.lux
index 1ed87f1e8..12c32b853 100644
--- a/stdlib/source/lux/math.lux
+++ b/stdlib/source/lux/math.lux
@@ -76,26 +76,22 @@
   [pow   "invokestatic:java.lang.Math:pow:double,double"]
   )
 
-(def: (gcd' a b)
-  (-> Int Int Int)
-  (case b
-    0 a
-    _ (gcd' b (i.% b a))))
-
 (def: #export (gcd a b)
   {#;doc "Greatest Common Divisor."}
-  (-> Int Int Int)
-  (gcd' (Int/abs a) (Int/abs b)))
+  (-> Nat Nat Nat)
+  (case b
+    +0 a
+    _ (gcd b (n.% b a))))
 
 (def: #export (lcm x y)
   {#;doc "Least Common Multiple."}
-  (-> Int Int Int)
+  (-> Nat Nat Nat)
   (case [x y]
-    (^or [_ 0] [0 _])
-    0
+    (^or [_ +0] [+0 _])
+    +0
 
     _
-    (|> x (i./ (gcd x y)) (i.* y) Int/abs)
+    (|> x (n./ (gcd x y)) (n.* y))
     ))
 
 ## [Syntax]
diff --git a/stdlib/source/lux/math/ratio.lux b/stdlib/source/lux/math/ratio.lux
index 5fb82c8a5..c2c9e7183 100644
--- a/stdlib/source/lux/math/ratio.lux
+++ b/stdlib/source/lux/math/ratio.lux
@@ -24,7 +24,8 @@
 
 (def: #hidden (normalize (^slots [#numerator #denominator]))
   (-> Ratio Ratio)
-  (let [common (math;gcd numerator denominator)
+  (let [common (nat-to-int (math;gcd (int-to-nat (i:abs numerator))
+                                     (int-to-nat (i:abs denominator))))
         numerator (i./ common numerator)
         denominator (i./ common denominator)]
     {#numerator (if (and (i.< 0 numerator)