diff --git a/.gitignore b/.gitignore
index 863e68d5..b765c8ea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 target/
 AwsCredentials.properties
 .idea
+amazon-kinesis-client.iml
\ No newline at end of file
diff --git a/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/exceptions/MissingIncompleteLeasesException.java b/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/exceptions/MissingIncompleteLeasesException.java
new file mode 100644
index 00000000..3af368ef
--- /dev/null
+++ b/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/exceptions/MissingIncompleteLeasesException.java
@@ -0,0 +1,16 @@
+package com.fivetran.external.com.amazonaws.services.kinesis.clientlibrary.exceptions;
+
+import java.util.Set;
+
+public class MissingIncompleteLeasesException extends RuntimeException {
+   private final Set<String> leases;
+
+    public MissingIncompleteLeasesException(Set<String> leases) {
+        super("missing leases: " + String.join(",", leases));
+        this.leases = leases;
+    }
+
+    public Set<String> getLeases() {
+        return leases;
+    }
+}
diff --git a/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/lib/worker/ShardSyncer.java b/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/lib/worker/ShardSyncer.java
index 02563196..7a96c396 100644
--- a/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/lib/worker/ShardSyncer.java
+++ b/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/lib/worker/ShardSyncer.java
@@ -30,6 +30,7 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.commons.lang3.StringUtils;
 
+import com.fivetran.external.com.amazonaws.services.kinesis.clientlibrary.exceptions.MissingIncompleteLeasesException;
 import com.fivetran.external.com.amazonaws.services.kinesis.clientlibrary.exceptions.internal.KinesisClientLibIOException;
 import com.fivetran.external.com.amazonaws.services.kinesis.clientlibrary.proxies.IKinesisProxy;
 import com.fivetran.external.com.amazonaws.services.kinesis.clientlibrary.types.ExtendedSequenceNumber;
@@ -610,10 +611,11 @@ class ShardSyncer {
                 garbageLeases.add(lease);
             }
         }
-        
+
         if (!garbageLeases.isEmpty()) {
+            Set<String> unfinishedAndMissing = new HashSet<>();
             LOG.info("Found " + garbageLeases.size()
-                    + " candidate leases for cleanup. Refreshing list of" 
+                    + " candidate leases for cleanup. Refreshing list of"
                     + " Kinesis shards to pick up recent/latest shards");
             List<Shard> currentShardList = getShardList(kinesisProxy);
             Set<String> currentKinesisShardIds = new HashSet<>();
@@ -623,11 +625,17 @@ class ShardSyncer {
 
             for (KinesisClientLease lease : garbageLeases) {
                 if (isCandidateForCleanup(lease, currentKinesisShardIds)) {
-                    LOG.info("Deleting lease for shard " + lease.getLeaseKey()
-                            + " as it is not present in Kinesis stream.");
-                    leaseManager.deleteLease(lease);
+                    if (lease.isCompete()) {
+                        LOG.info("Deleting lease for a complete shard " + lease.getLeaseKey()
+                                + " as it is not present in Kinesis stream.");
+                        leaseManager.deleteLease(lease);
+                    } else {
+                        unfinishedAndMissing.add(lease.getLeaseKey());
+                    }
                 }
             }
+
+            if (!unfinishedAndMissing.isEmpty()) throw new MissingIncompleteLeasesException(unfinishedAndMissing);
         }
         
     }
@@ -694,7 +702,7 @@ class ShardSyncer {
         Set<String> shardIdsOfClosedShards = new HashSet<>();
         List<KinesisClientLease> leasesOfClosedShards = new ArrayList<>();
         for (KinesisClientLease lease : currentLeases) {
-            if (lease.getCheckpoint().equals(ExtendedSequenceNumber.SHARD_END)) {
+            if (lease.isCompete()) {
                 shardIdsOfClosedShards.add(lease.getLeaseKey());
                 leasesOfClosedShards.add(lease);
             }
diff --git a/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/lib/worker/Worker.java b/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/lib/worker/Worker.java
index f4e2d0fc..04b56a74 100644
--- a/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/lib/worker/Worker.java
+++ b/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/clientlibrary/lib/worker/Worker.java
@@ -32,6 +32,7 @@ import java.util.function.Consumer;
 
 import com.amazonaws.services.dynamodbv2.model.AmazonDynamoDBException;
 import com.amazonaws.services.dynamodbv2.model.TrimmedDataAccessException;
+import com.fivetran.external.com.amazonaws.services.kinesis.clientlibrary.exceptions.MissingIncompleteLeasesException;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -528,6 +529,7 @@ public class Worker implements Runnable {
             throw e;
         } catch (Exception e) {
             handleTrimmedDataAccessException(e);
+            handleMissingIncompleteLeasesException(e);
 
             if (causedByStreamRecordProcessingError(e))
                 throw new RuntimeException("Failing worker after irrecoverable failure: " + e.getMessage());
@@ -561,12 +563,36 @@ public class Worker implements Runnable {
     }
 
     private Optional<TrimmedDataAccessException> getTrimmedDataAccessException(Throwable t) {
-        if (t.getCause() == null) return Optional.empty();
-        if (t.getCause().getClass().equals(TrimmedDataAccessException.class)) return Optional.of( (TrimmedDataAccessException) t.getCause());
+        if (t.getClass().equals(TrimmedDataAccessException.class)) {
+            return Optional.of( (TrimmedDataAccessException) t);
+        }
+        if (t.getCause().getClass().equals(TrimmedDataAccessException.class)) {
+            return Optional.of( (TrimmedDataAccessException) t.getCause());
+        } else if (t.getCause() == null) {
+            return Optional.empty();
+        }
 
         return getTrimmedDataAccessException(t.getCause());
     }
 
+    private void handleMissingIncompleteLeasesException(Exception e) {
+        Optional<MissingIncompleteLeasesException> maybeMissingLeaseException = getMissingIncompleteLeasesException(e);
+        if (maybeMissingLeaseException.isPresent()) throw maybeMissingLeaseException.get();
+    }
+
+    private Optional<MissingIncompleteLeasesException> getMissingIncompleteLeasesException(Throwable t) {
+        if (t.getClass().equals(MissingIncompleteLeasesException.class)) {
+            return Optional.of( (MissingIncompleteLeasesException) t);
+        }
+        if (t.getCause().getClass().equals(MissingIncompleteLeasesException.class)) {
+            return Optional.of( (MissingIncompleteLeasesException) t.getCause());
+        } else if (t.getCause() == null) {
+            return Optional.empty();
+        }
+
+        return getMissingIncompleteLeasesException(t.getCause());
+    }
+
     private void initialize() {
         workerStateChangeListener.onWorkerStateChange(WorkerStateChangeListener.WorkerState.INITIALIZING);
         boolean isDone = false;
@@ -600,7 +626,10 @@ public class Worker implements Runnable {
                     isDone = true;
                 } else {
                     lastException = result.getException();
+                    handleMissingIncompleteLeasesException(lastException);
                 }
+            } catch (MissingIncompleteLeasesException e) {
+                throw e;
             } catch (LeasingException e) {
                 LOG.error("Caught exception when initializing LeaseCoordinator", e);
                 lastException = e;
diff --git a/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/leases/impl/KinesisClientLease.java b/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/leases/impl/KinesisClientLease.java
index 2afa2e0f..d4605e27 100644
--- a/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/leases/impl/KinesisClientLease.java
+++ b/src/main/java/com/fivetran/external/com/amazonaws/services/kinesis/leases/impl/KinesisClientLease.java
@@ -71,6 +71,10 @@ public class KinesisClientLease extends Lease {
         setParentShardIds(casted.parentShardIds);
     }
 
+    public boolean isCompete() {
+        return checkpoint.equals(ExtendedSequenceNumber.SHARD_END);
+    }
+
     /**
      * @return most recently application-supplied checkpoint value. During fail over, the new worker will pick up after
      *         the old worker's last checkpoint.