diff --git a/ivory-eval.cabal b/ivory-eval.cabal
--- a/ivory-eval.cabal
+++ b/ivory-eval.cabal
@@ -1,5 +1,5 @@
 name:                ivory-eval
-version:             0.1.0.4
+version:             0.1.0.5
 author:              Galois, Inc.
 copyright:           2014 Galois, Inc.
 maintainer:          leepike@galois.com
diff --git a/src/Ivory/Eval.hs b/src/Ivory/Eval.hs
--- a/src/Ivory/Eval.hs
+++ b/src/Ivory/Eval.hs
@@ -115,7 +115,7 @@
 
 or :: Value -> Value -> Value
 or (Bool x) (Bool y) = Bool (x || y)
-or x        y        = error $ "invalid operors to `or`: " ++ show (x,y)
+or x        y        = error $ "invalid operands to `or`: " ++ show (x,y)
 
 ordOp :: (forall a. Ord a => a -> a -> Bool) -> Value -> Value -> Value
 ordOp op (Sint8  x) (Sint8  y) = Bool (op x y)