diff --git a/src/contact.ts b/src/contact.ts
index 3271341..7fd422b 100644
--- a/src/contact.ts
+++ b/src/contact.ts
@@ -21,12 +21,12 @@ export class Contact {
 
 		const { name, address } = custom[shortName as keyof typeof custom]
 
-		if (name !== 'string') {
+		if (typeof name !== 'string') {
 			throw new SyntaxError(
 				`missing key "name" in contact short name config for "${shortName}"`,
 			)
 		}
-		if (address !== 'string') {
+		if (typeof address !== 'string') {
 			throw new SyntaxError(
 				`missing key "address" in contact short name config for "${shortName}"`,
 			)