diff --git a/.circleci/config.yml b/.circleci/config.yml
index c7a34563355d1c80c3b31ee076ac1cc002ab3036..2751d76e936cad3631f0337504120e76316bb7c1 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -120,6 +120,9 @@ jobs:
             # dependencies into the environment.
             venv/bin/pip install --no-index --find-links file://${PWD}/wheelhouse .[test]
 
+            # For a while we depend on a pretty fresh Tahoe
+            pip install https://github.com/tahoe-lafs/tahoe-lafs/archive/refs/heads/3842.allocate_buckets-without-lease-renewal.zip
+
       - run:
           name: "Test"
           command: |
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 8ad846a84580a397c4b451643c401b80e5d2e438..66cf508aeccb93cd357f9384a0304cd2028744ff 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -40,6 +40,8 @@ jobs:
     - name: "Install ZKAPAuthorizer and dependencies"
       run: |
         python -m pip install -v ./[test]
+        # For a while we depend on a pretty fresh Tahoe
+        pip install https://github.com/tahoe-lafs/tahoe-lafs/archive/refs/heads/3842.allocate_buckets-without-lease-renewal.zip
 
     - name: "Dump Python Environment"
       run: |