diff --git a/src/pim-types.ts b/src/pim-types.ts
index ea0f846..6a8739b 100644
--- a/src/pim-types.ts
+++ b/src/pim-types.ts
@@ -14,6 +14,7 @@ export interface PimType {
   itemUid?: string;
   toIcal(): string;
   clone(): PimType;
+  lastModified: ICAL.Time | undefined;
 }
 
 export function timezoneLoadFromName(timezone: string | null) {
@@ -385,6 +386,10 @@ export class ContactType implements PimType {
     return this.comp.getFirstPropertyValue("bday");
   }
 
+  get lastModified() {
+    return this.comp.getFirstPropertyValue("rev");
+  }
+
   get group() {
     const kind = this.comp.getFirstPropertyValue("kind");
     return ["group", "organization"].includes(kind);