diff --git a/fields.js b/fields.js
index 9e0af38..c75ccd4 100644
--- a/fields.js
+++ b/fields.js
@@ -25,7 +25,7 @@ class FieldsContainer {
 			fields = fields[0];
 		}
 
-		let validFields = fields.filter(f => typeof f === "object" && schema.isValid(f, schema.constants.field));
+		let validFields = fields.filter(f => typeof f === "object" && schema.isValid(f, "field"));
 
 		this.fields.push(...validFields);
 
diff --git a/index.js b/index.js
index 5f7a043..99419b3 100644
--- a/index.js
+++ b/index.js
@@ -239,7 +239,7 @@ class Pass {
 				data = [data];
 			}
 
-			let valid = data.filter(d => schema.isValid(d, schema.constants[type+"Dict"]));
+			let valid = data.filter(d => schema.isValid(d, type+"Dict"));
 			this.props[type] = valid;
 
 			return Object.assign({
@@ -302,10 +302,7 @@ class Pass {
 				return false;
 			}
 
-			// messageEncoding is required
-			// b.messageEncoding = b.messageEncoding || "iso-8859-1";
-
-			return schema.isValid(b, schema.constants.barcode);
+			return schema.isValid(b, "barcode");
 		});
 
 		this.props["barcode"] = valid[0] || {};
@@ -406,7 +403,7 @@ class Pass {
 			data = data[0];
 		}
 
-		let valid = data.filter(d => d instanceof Object && schema.isValid(d, schema.constants.nfcDict));
+		let valid = data.filter(d => d instanceof Object && schema.isValid(d, "nfcDict"));
 
 		this.props["nfc"] = valid;
 
@@ -435,7 +432,7 @@ class Pass {
 			let type = passTypes[index];
 
 			this.type = type;
-			return schema.isValid(passFile[type], schema.constants.passDict);
+			return schema.isValid(passFile[type], "passDict");
 		} catch (e) {
 			return false;
 		}
@@ -564,7 +561,7 @@ class Pass {
 	 */
 
 	_parseSettings(options) {
-		if (!schema.isValid(options, schema.constants.instance)) {
+		if (!schema.isValid(options, "instance")) {
 			throw new Error(errors.REQS_NOT_MET);
 		}
 
@@ -574,7 +571,7 @@ class Pass {
 
 		this.model = path.resolve(options.model) + (!!options.model && !path.extname(options.model) ? ".pass" : "");
 
-		const filteredOpts = schema.filter(options, schema.constants.supportedOptions);
+		const filteredOpts = schema.filter(options.overrides, "supportedOptions");
 
 		Object.assign(this.props, filteredOpts);
 
@@ -606,7 +603,7 @@ class Pass {
 	}
 
 	set transitType(v) {
-		if (schema.isValid(v, schema.constants.transitType)) {
+		if (schema.isValid(v, "transitType")) {
 			this._transitType = v;
 		} else {
 			this._transitType = this._transitType || "";
diff --git a/schema.js b/schema.js
index 7c32f99..7eb05c5 100644
--- a/schema.js
+++ b/schema.js
@@ -2,7 +2,7 @@ const Joi = require("joi");
 const debug = require("debug")("Schema");
 
 let instance = Joi.object().keys({
-	model: Joi.string(),
+	model: Joi.string().required(),
 	certificates: Joi.object().keys({
 		wwdr: Joi.string().required(),
 		signerCert: Joi.string().required(),
@@ -94,8 +94,31 @@ let nfcDict = Joi.object().keys({
 	encryptionPublicKey: Joi.string()
 });
 
+let schemas = {
+	instance,
+	barcode,
+	field,
+	passDict,
+	beaconsDict,
+	locationsDict,
+	transitType,
+	nfcDict,
+	supportedOptions
+};
+
+let resolveSchemaName = (name) => {
+	return schemas[name] || "";
+};
+
 let isValid = (opts, schemaName) => {
-	let validation = Joi.validate(opts, schemaName);
+	let resolvedSchema = resolveSchemaName(schemaName);
+
+	if (!resolvedSchema) {
+		debug(`validation failed due to missing or mispelled schema name`);
+		return false;
+	}
+
+	let validation = Joi.validate(opts, resolvedSchema);
 
 	if (validation.error) {
 		debug(`validation failed due to error: ${validation.error.message}`);
@@ -121,17 +144,6 @@ let filter = (opts, schemaName) => {
 }
 
 module.exports = {
-	constants: {
-		instance,
-		barcode,
-		field,
-		passDict,
-		beaconsDict,
-		locationsDict,
-		transitType,
-		nfcDict,
-		supportedOptions
-	},
 	isValid,
 	filter
 };