diff --git a/ballerina/Dependencies.toml b/ballerina/Dependencies.toml
index 0015ee2d..35d69305 100644
--- a/ballerina/Dependencies.toml
+++ b/ballerina/Dependencies.toml
@@ -112,7 +112,7 @@ modules = [
 [[package]]
 org = "ballerina"
 name = "observe"
-version = "1.2.0"
+version = "1.2.3"
 dependencies = [
 	{org = "ballerina", name = "jballerina.java"}
 ]
diff --git a/ballerina/listener_endpoint.bal b/ballerina/listener_endpoint.bal
index 8ce722b3..589cece5 100644
--- a/ballerina/listener_endpoint.bal
+++ b/ballerina/listener_endpoint.bal
@@ -14,12 +14,12 @@
 // specific language governing permissions and limitations
 // under the License.
 
+import ballerina/jballerina.java;
 import ballerina/log;
 import ballerina/task;
-import ballerina/jballerina.java;
 
 # Represents a service listener that monitors the FTP location.
-public class Listener {
+public isolated class Listener {
 
     private handle EMPTY_JAVA_STRING = java:fromString("");
     private ListenerConfiguration config = {};
@@ -30,8 +30,10 @@ public class Listener {
     # + listenerConfig - Configurations for FTP listener
     # + return - `()` or else an `ftp:Error` upon failure to initialize the listener
     public isolated function init(ListenerConfiguration listenerConfig) returns Error? {
-        self.config = listenerConfig;
-        return initListener(self, self.config);
+        self.config = listenerConfig.clone();
+        lock {
+            return initListener(self, self.config);
+        }
     }
 
     # Starts the `ftp:Listener`.
@@ -91,13 +93,17 @@ public class Listener {
     }
 
     isolated function internalStart() returns error? {
-        self.jobId = check task:scheduleJobRecurByFrequency(new Job(self), self.config.pollingInterval);
+        lock {
+            self.jobId = check task:scheduleJobRecurByFrequency(new Job(self), self.config.pollingInterval);
+        }
     }
 
     isolated function stop() returns error? {
-        var id = self.jobId;
-        if id is task:JobId {
-            check task:unscheduleJob(id);
+        lock {
+            var id = self.jobId;
+            if id is task:JobId {
+                check task:unscheduleJob(id);
+            }
         }
     }
 
diff --git a/changelog.md b/changelog.md
index ffe0aff6..1c8b1fcd 100644
--- a/changelog.md
+++ b/changelog.md
@@ -3,6 +3,12 @@ This file contains all the notable changes done to the Ballerina Email package t
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Fixed
+
+- [Isolated the `ftp:Listener`](https://github.com/ballerina-platform/module-ballerina-ftp/pull/1287)
+
 ## [2.10.1] - 2024-07-24
 
 ## Added