diff --git a/csound-expression-typed.cabal b/csound-expression-typed.cabal
--- a/csound-expression-typed.cabal
+++ b/csound-expression-typed.cabal
@@ -1,5 +1,5 @@
 Name:          csound-expression-typed
-Version:       0.0.9.2
+Version:       0.0.9.3
 Cabal-Version: >= 1.22
 License:       BSD3
 License-file:  LICENSE
diff --git a/src/Csound/Typed/Types/Prim.hs b/src/Csound/Typed/Types/Prim.hs
--- a/src/Csound/Typed/Types/Prim.hs
+++ b/src/Csound/Typed/Types/Prim.hs
@@ -381,13 +381,13 @@
     fromGE = BoolSig 
     toGE x = case x of
         BoolSig a -> a
-        PrimBoolSig b -> return $ if b then 1 else 0
+        PrimBoolSig b -> return $ if b then true else false
 
 instance Val BoolD   where 
     fromGE = BoolD
     toGE x = case x of
         BoolD a -> a
-        PrimBoolD b -> return $ if b then 1 else 0   
+        PrimBoolD b -> return $ if b then true else false
 
 
 class (IsPrim a, RealFrac (PrimOf a), Val a) => SigOrD a where