diff --git a/pageserver/src/tenant_threads.rs b/pageserver/src/tenant_threads.rs
index 349a1f7060..ce75df21bb 100644
--- a/pageserver/src/tenant_threads.rs
+++ b/pageserver/src/tenant_threads.rs
@@ -1,6 +1,7 @@
 //! This module contains functions to serve per-tenant background processes,
 //! such as compaction and GC
 
+use std::collections::HashMap;
 use std::ops::ControlFlow;
 
 use crate::repository::Repository;
@@ -10,6 +11,7 @@ use crate::{tenant_mgr, thread_mgr};
 use anyhow::{self, Context};
 use once_cell::sync::OnceCell;
 use tokio::sync::mpsc::{self, Sender};
+use tokio::task::JoinHandle;
 use tracing::*;
 use utils::zid::ZTenantId;
 
@@ -115,6 +117,10 @@ pub fn init_tenant_task_pool() -> anyhow::Result<()> {
         .set(compaction_send)
         .expect("Failed to set START_COMPACTION_LOOP");
 
+    // TODO this is getting repetitive
+    let mut gc_loops = HashMap::<ZTenantId, JoinHandle<Result<(), anyhow::Error>>>::new();
+    let mut compaction_loops = HashMap::<ZTenantId, JoinHandle<Result<(), anyhow::Error>>>::new();
+
     thread_mgr::spawn(
         ThreadKind::TenantTaskManager,
         None,
@@ -126,18 +132,29 @@ pub fn init_tenant_task_pool() -> anyhow::Result<()> {
                 loop {
                     tokio::select! {
                         _ = thread_mgr::shutdown_watcher() => {
-                            // TODO cancel all running tasks
-                            break
+                            for (_, handle) in gc_loops.drain() {
+                                handle.abort();
+                            }
+                            for (_, handle) in compaction_loops.drain() {
+                                handle.abort();
+                            }
+                            break;
                         },
                         tenantid = gc_recv.recv() => {
                             let tenantid = tenantid.expect("Gc task channel closed unexpectedly");
-                            // TODO cancel existing loop, if any.
-                            tokio::spawn(gc_loop(tenantid));
+                            let new_handle = tokio::spawn(gc_loop(tenantid));
+                            if let Some(old_handle) = gc_loops.insert(tenantid, new_handle) {
+                                // TODO use non-blocking cancel chan instead
+                                old_handle.abort();
+                            }
                         },
                         tenantid = compaction_recv.recv() => {
                             let tenantid = tenantid.expect("Compaction task channel closed unexpectedly");
-                            // TODO cancel existing loop, if any.
-                            tokio::spawn(compaction_loop(tenantid));
+                            let new_handle = tokio::spawn(compaction_loop(tenantid));
+                            if let Some(old_handle) = compaction_loops.insert(tenantid, new_handle) {
+                                // TODO use non-blocking cancel chan instead
+                                old_handle.abort();
+                            }
                         },
                     }
                 }