diff --git a/clients/python/src/taskbroker_client/constants.py b/clients/python/src/taskbroker_client/constants.py
index 6655c199..383a2b0f 100644
--- a/clients/python/src/taskbroker_client/constants.py
+++ b/clients/python/src/taskbroker_client/constants.py
@@ -46,6 +46,12 @@
 The maximum number of bytes before a task parameter is compressed.
 """
 
+DEFAULT_GRPC_MAX_MESSAGE_SIZE = 10 * 1024 * 1024  # 10MB
+"""
+The maximum size of a gRPC message in bytes.
+Can be overridden via TASKBROKER_GRPC_MAX_MESSAGE_SIZE env var.
+"""
+
 DEFAULT_WORKER_HEALTH_CHECK_SEC_PER_TOUCH = 1.0
 """
 The number of gRPC requests before touching the health check file
diff --git a/clients/python/src/taskbroker_client/worker/worker.py b/clients/python/src/taskbroker_client/worker/worker.py
index 86327dec..357d4708 100644
--- a/clients/python/src/taskbroker_client/worker/worker.py
+++ b/clients/python/src/taskbroker_client/worker/worker.py
@@ -2,6 +2,7 @@
 
 import logging
 import multiprocessing
+import os
 import queue
 import signal
 import threading
@@ -23,6 +24,7 @@
 
 from taskbroker_client.app import import_app
 from taskbroker_client.constants import (
+    DEFAULT_GRPC_MAX_MESSAGE_SIZE,
     DEFAULT_REBALANCE_AFTER,
     DEFAULT_WORKER_HEALTH_CHECK_SEC_PER_TOUCH,
     DEFAULT_WORKER_QUEUE_SIZE,
@@ -261,9 +263,16 @@ def signal_handler(*args: Any) -> None:
             if self._grpc_secrets:
                 interceptors = [RequestSignatureServerInterceptor(self._grpc_secrets)]
 
+            max_message_size = int(
+                os.environ.get("TASKBROKER_GRPC_MAX_MESSAGE_SIZE", DEFAULT_GRPC_MAX_MESSAGE_SIZE)
+            )
             server = grpc.server(
                 ThreadPoolExecutor(max_workers=self._concurrency),
                 interceptors=interceptors,
+                options=[
+                    ("grpc.max_receive_message_length", max_message_size),
+                    ("grpc.max_send_message_length", max_message_size),
+                ],
             )
 
             taskbroker_pb2_grpc.add_WorkerServiceServicer_to_server(
diff --git a/src/config.rs b/src/config.rs
index a5fedf3a..17705933 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -268,6 +268,10 @@ pub struct Config {
     /// If a message is bigger than this then the produce will fail.
     pub max_message_size: u64,
 
+    /// The maximum size in bytes for gRPC messages sent to workers.
+    /// Should be at least as large as max_message_size.
+    pub grpc_max_message_size: usize,
+
     /// The number of pages to vacuum from sqlite when vacuum is run.
     /// If None, all pages will be vacuumed.
     pub vacuum_page_count: Option<usize>,
@@ -420,6 +424,7 @@ impl Default for Config {
             maintenance_task_interval_ms: 6000,
             max_delayed_task_allowed_sec: 3600,
             max_message_size: 5000000,
+            grpc_max_message_size: 10 * 1024 * 1024, // 10MB
             vacuum_page_count: None,
             full_vacuum_on_start: true,
             full_vacuum_on_upkeep: true,
diff --git a/src/worker.rs b/src/worker.rs
index 29250ff7..2942ce41 100644
--- a/src/worker.rs
+++ b/src/worker.rs
@@ -57,7 +57,12 @@ pub struct Worker {
 
 impl Worker {
     pub async fn connect(config: Arc<Config>, endpoint: String) -> Result<Self> {
-        let client = WorkerServiceClient::connect(endpoint).await?;
+        let channel = tonic::transport::Channel::from_shared(endpoint)?
+            .connect()
+            .await?;
+        let client = WorkerServiceClient::new(channel)
+            .max_encoding_message_size(config.grpc_max_message_size)
+            .max_decoding_message_size(config.grpc_max_message_size);
 
         let secrets = config.grpc_shared_secret.clone();
         let timeout = Duration::from_millis(config.push_timeout_ms);