diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6dd06bc..3db0982 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -43,6 +43,8 @@ jobs:
       - uses: actions/checkout@v4
       - name: Cache the store
         uses: ./
+        with:
+          strict-mode: true
 
   run-x86_64-linux-untrusted:
     name: Run x86_64 Linux, Untrusted
@@ -63,6 +65,8 @@ jobs:
             trusted-users = root
       - name: Cache the store
         uses: ./
+        with:
+          strict-mode: true
       - name: Check the cache isn't enabled
         run: |
           [ $(nix config show substituters) == "https://cache.nixos.org/" ]
@@ -85,6 +89,8 @@ jobs:
             narinfo-cache-negative-ttl = 0
       - name: Cache the store
         uses: ./
+        with:
+          strict-mode: true
       - name: Check the cache for liveness
         run: |
           .github/workflows/cache-test.sh
@@ -107,6 +113,8 @@ jobs:
             narinfo-cache-negative-ttl = 0
       - name: Cache the store
         uses: ./
+        with:
+          strict-mode: true
       - name: Check the cache for liveness
         run: |
           .github/workflows/cache-test.sh
@@ -130,6 +138,8 @@ jobs:
             narinfo-cache-negative-ttl = 0
       - name: Cache the store
         uses: ./
+        with:
+          strict-mode: true
       - name: Check the cache for liveness
         run: |
           .github/workflows/cache-test.sh
diff --git a/action.yml b/action.yml
index 14fd3cc..442d900 100644
--- a/action.yml
+++ b/action.yml
@@ -52,7 +52,7 @@ inputs:
     description: A URL pointing to a `magic-nix-cache` binary. Overrides all other `source-*` options.
     required: false
   strict-mode:
-    description: "Whether to fail when any errors are thrown. Used only to test the Action; do not set this in your own workflows."
+    description: Whether to fail when any errors are thrown. Used only to test the Action; do not set this in your own workflows.
     default: false
     required: false