diff --git a/package.json b/package.json
index 93e5945..7784cdc 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@uci-utils/to-boolean",
-  "version": "0.1.3",
+  "version": "0.1.4",
   "description": "function to return a boolean value from sets of default values",
   "main": "src/boolean.js",
   "scripts": {
diff --git a/src/boolean.js b/src/boolean.js
index 958b735..00b0ecc 100644
--- a/src/boolean.js
+++ b/src/boolean.js
@@ -5,8 +5,8 @@ function createBoolean (opts={}) {
   return (value => {
     if (opts.addTrue) rTrue = rTrue.concat(opts.addTrue)
     if (opts.addFalse) rFalse = rFalse.concat(opts.addFalse)
-    if (value===undefined) return opts.undefined==='same' ? undefined : opts.undefined || false
-    if (value===null) return opts.null==='same' ? null : opts.null || false
+    if (value===undefined) return opts.undefined==='same' ? undefined : (opts.undefined || false)
+    if (value===null) return opts.null==='same' ? null : (opts.null || false)
     if (!isNaN(Number(value))) return (opts.number==='default' ? !!value : (Number(value) > (opts.number || 0)? true : false))
     if (typeof value==='string') {
       value = value.trim()