diff --git a/src/pass.ts b/src/pass.ts
index c4c8c64..15d571f 100644
--- a/src/pass.ts
+++ b/src/pass.ts
@@ -30,13 +30,15 @@ export class Pass {
 	private [passProps]: schema.ValidPass = {};
 	private type: keyof schema.ValidPassType;
 	private fieldsKeys: Set<string> = new Set<string>();
-	private passCore: schema.ValidPass = {};
+	private passCore: schema.ValidPass;
 
-	public headerFields: FieldsArray;
-	public primaryFields: FieldsArray;
-	public secondaryFields: FieldsArray;
-	public auxiliaryFields: FieldsArray;
-	public backFields: FieldsArray;
+	// Setting these as possibly undefined because we set
+	// them all in an loop later
+	public headerFields: FieldsArray | undefined;
+	public primaryFields: FieldsArray | undefined;
+	public secondaryFields: FieldsArray | undefined;
+	public auxiliaryFields: FieldsArray | undefined;
+	public backFields: FieldsArray | undefined;
 
 	private Certificates: schema.FinalCertificates;
 	private [transitType]: string = "";
@@ -72,7 +74,8 @@ export class Pass {
 		}
 
 		// Parsing and validating pass.json keys
-		const validatedPassKeys = Object.keys(this.passCore).reduce((acc, current) => {
+		const passCoreKeys = Object.keys(this.passCore) as (keyof schema.ValidPass)[];
+		const validatedPassKeys = passCoreKeys.reduce((acc, current) => {
 			if (this.type === current) {
 				// We want to exclude type keys (eventTicket,
 				// boardingPass, ecc.) and their content
@@ -86,10 +89,13 @@ export class Pass {
 				return { ...acc, [current]: this.passCore[current] };
 			}
 
-			const currentSchema = propsSchemaMap.get(current);
+			const currentSchema = propsSchemaMap.get(current)!;
 
 			if (Array.isArray(this.passCore[current])) {
-				const valid = getValidInArray(currentSchema, this.passCore[current]);
+				const valid = getValidInArray<schema.ArrayPassSchema>(
+					currentSchema,
+					this.passCore[current] as schema.ArrayPassSchema[]
+				);
 				return { ...acc, [current]: valid };
 			} else {
 				return {
@@ -201,7 +207,7 @@ export class Pass {
 		* and returning the compiled manifest
 		*/
 		const archive = new ZipFile();
-		const manifest = Object.keys(finalBundle).reduce((acc, current) => {
+		const manifest = Object.keys(finalBundle).reduce<schema.Manifest>((acc, current) => {
 			let hashFlow = forge.md.sha1.create();
 
 			hashFlow.update(finalBundle[current].toString("binary"));
@@ -504,7 +510,7 @@ export class Pass {
 	 * @returns {Buffer}
 	 */
 
-	private _sign(manifest: { [key: string]: string }): Buffer {
+	private _sign(manifest: schema.Manifest): Buffer {
 		const signature = forge.pkcs7.createSignedData();
 
 		signature.content = forge.util.createBuffer(JSON.stringify(manifest), "utf8");
@@ -577,8 +583,8 @@ export class Pass {
 			 * and then delete it from the passFile.
 			 */
 
-			["backgroundColor", "foregroundColor", "labelColor"]
-				.filter(v => this[passProps][v] && !isValidRGB(this[passProps][v]))
+			const passColors = ["backgroundColor", "foregroundColor", "labelColor"] as Array<keyof schema.PassColors>;
+			passColors.filter(v => this[passProps][v] && !isValidRGB(this[passProps][v]))
 				.forEach(v => delete this[passProps][v]);
 
 			Object.assign(passFile, this[passProps]);
@@ -630,7 +636,7 @@ function barcodesFromUncompleteData(message: string): schema.Barcode[] {
 		"PKBarcodeFormatPDF417",
 		"PKBarcodeFormatAztec",
 		"PKBarcodeFormatCode128"
-	].map(format => schema.getValidated({ format, message }, "barcode"));
+	].map(format => schema.getValidated({ format, message }, "barcode") as schema.Barcode);
 }
 
 function processRelevancySet<T>(key: string, data: T[]): T[] {
diff --git a/src/schema.ts b/src/schema.ts
index a4eec48..bbf57ac 100644
--- a/src/schema.ts
+++ b/src/schema.ts
@@ -3,6 +3,10 @@ import debug from "debug";
 
 const schemaDebug = debug("Schema");
 
+export interface Manifest {
+	[key: string]: string;
+}
+
 export interface Certificates {
 	wwdr?: string;
 	signerCert?: string;
@@ -71,7 +75,7 @@ export interface OverridesSupportedOptions {
 	teamIdentifier?: string;
 	appLaunchURL?: string;
 	associatedStoreIdentifiers?: Array<number>;
-	userInfo?: Object | Array<any>;
+	userInfo?: { [key: string]: any };
 	webServiceURL?: string;
 	authenticationToken?: string;
 	sharingProhibited?: boolean;
@@ -294,7 +298,7 @@ export interface ValidPassType {
 	storeCard?: PassFields;
 }
 
-export interface ValidPass extends OverridesSupportedOptions, ValidPassType {
+interface PassInterfacesProps {
 	barcode?: Barcode;
 	barcodes?: Barcode[];
 	beacons?: Beacon[];
@@ -306,6 +310,12 @@ export interface ValidPass extends OverridesSupportedOptions, ValidPassType {
 	voided?: boolean;
 }
 
+type AllPassProps = PassInterfacesProps & ValidPassType & OverridesSupportedOptions;
+export type ValidPass = {
+	[K in keyof AllPassProps]: AllPassProps[K];
+};
+export type PassColors = Pick<OverridesSupportedOptions, "backgroundColor" | "foregroundColor" | "labelColor">;
+
 export interface Barcode {
 	altText?: string;
 	messageEncoding?: string;
@@ -464,6 +474,7 @@ const schemas = {
 };
 
 export type Schema = keyof typeof schemas;
+export type ArrayPassSchema = Beacon | Location | Barcode;
 
 function resolveSchemaName(name: Schema) {
 	return schemas[name] || undefined;
@@ -500,7 +511,7 @@ export function isValid(opts: any, schemaName: Schema): boolean {
  * @returns {object} the filtered value or empty object
  */
 
-export function getValidated<T extends Object>(opts: any, schemaName: Schema): T {
+export function getValidated<T extends Object>(opts: any, schemaName: Schema): T | null {
 	const resolvedSchema = resolveSchemaName(schemaName);
 
 	if (!resolvedSchema) {
diff --git a/src/utils.ts b/src/utils.ts
index 1e42384..539f471 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -11,7 +11,7 @@ import { sep } from "path";
  * @returns {Boolean} True if valid rgb, false otherwise
  */
 
-export function isValidRGB(value: string): boolean {
+export function isValidRGB(value?: string): boolean {
 	if (!value || typeof value !== "string") {
 		return false;
 	}
@@ -89,8 +89,10 @@ export function generateStringFile(lang: { [index: string]: string }): Buffer {
  * @param origin
  */
 
-export function splitBufferBundle(origin: Object): [PartitionedBundle["l10nBundle"], PartitionedBundle["bundle"]] {
-	return Object.keys(origin).reduce(([ l10n, bundle ], current) => {
+type PartitionedBundleElements = [PartitionedBundle["l10nBundle"], PartitionedBundle["bundle"]];
+
+export function splitBufferBundle(origin: any): PartitionedBundleElements {
+	return Object.keys(origin).reduce<PartitionedBundleElements>(([ l10n, bundle ], current) => {
 		if (!current.includes(".lproj")) {
 			return [ l10n, { ...bundle, [current]: origin[current] }];
 		}