diff --git a/src/Socket/messages-recv.ts b/src/Socket/messages-recv.ts
index d5772020..a67d9dba 100644
--- a/src/Socket/messages-recv.ts
+++ b/src/Socket/messages-recv.ts
@@ -1600,6 +1600,38 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 		}
 	}
 
+	/**
+	 * Sanitizes caller phone number to fix known decoder bugs
+	 *
+	 * Issue: Brazilian landline numbers (12 digits) incorrectly get a trailing zero
+	 * Example: 551738025555 → 5517380255550 (off-by-one error)
+	 *
+	 * This helper removes the trailing zero if:
+	 * - Number is 13 digits (incorrect length)
+	 * - Starts with '55' (Brazil country code)
+	 *
+	 * @param pn - Raw phone number from caller_pn attribute
+	 * @returns Sanitized phone number
+	 */
+	const sanitizeCallerPn = (pn: string | undefined): string | undefined => {
+		if (!pn) {
+			return undefined
+		}
+
+		// Fix Brazilian landline off-by-one bug
+		// Remove trailing zero if 13 digits and starts with Brazil code
+		if (pn.length === 13 && pn.startsWith('55')) {
+			const sanitized = pn.slice(0, -1)
+			logger.debug(
+				{ original: pn, sanitized },
+				'Call: Sanitized Brazilian landline number (removed trailing zero)'
+			)
+			return sanitized
+		}
+
+		return pn
+	}
+
 	const handleCall = async (node: BinaryNode) => {
 		const { attrs } = node
 		const [infoChild] = getAllBinaryNodeChildren(node)
@@ -1625,6 +1657,8 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 			call.isVideo = !!getBinaryNodeChild(infoChild, 'video')
 			call.isGroup = infoChild.attrs.type === 'group' || !!infoChild.attrs['group-jid']
 			call.groupJid = infoChild.attrs['group-jid']
+			// Extract and sanitize caller phone number
+			call.callerPn = sanitizeCallerPn(infoChild.attrs['caller_pn'])
 			await callOfferCache.set(call.id, call)
 		}
 
@@ -1634,6 +1668,9 @@ export const makeMessagesRecvSocket = (config: SocketConfig) => {
 		if (existingCall) {
 			call.isVideo = existingCall.isVideo
 			call.isGroup = existingCall.isGroup
+			call.groupJid = existingCall.groupJid
+			// Preserve callerPn across call state updates
+			call.callerPn = call.callerPn || existingCall.callerPn
 		}
 
 		// delete data once call has ended
diff --git a/src/Types/Call.ts b/src/Types/Call.ts
index 80972f62..83fe08b5 100644
--- a/src/Types/Call.ts
+++ b/src/Types/Call.ts
@@ -11,4 +11,6 @@ export type WACallEvent = {
 	status: WACallUpdateType
 	offline: boolean
 	latencyMs?: number
+	/** Phone number of the caller (sanitized to fix Brazilian landline bug) */
+	callerPn?: string
 }