diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index d6c2653..5becad7 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -32,9 +32,13 @@ jobs:
         uses: actions/cache@v4
         with:
           path: _build
-          key: nightly-prop-${{ hashFiles('rebar.lock') }}
+          # rebar.config is hashed too: test-profile deps (meck, proper) and the
+          # asobi git ref are not written to rebar.lock, so a lock-only key never
+          # busts when they bump. The -v2- prefix retires the poisoned pre-OTP-29
+          # caches (stale meck 0.9, pulled transitively via asobi).
+          key: nightly-prop-v2-${{ hashFiles('rebar.config', 'rebar.lock') }}
           restore-keys: |
-            nightly-prop-
+            nightly-prop-v2-
 
       - name: Run property tests at high numtests
         run: |