diff --git a/.github/workflows/ci.generate.ts b/.github/workflows/ci.generate.ts
index 1d68439d690e2e..35367adb871f33 100755
--- a/.github/workflows/ci.generate.ts
+++ b/.github/workflows/ci.generate.ts
@@ -10,6 +10,9 @@ const Runners = {
   macos: "macos-12",
   windows: `\${{ ${windowsRunnerCondition} }}`,
 };
+// bump the number at the start when you want to purge the cache
+const cacheKeyPrefix =
+  "18-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-";
 
 const installPkgsCommand =
   "sudo apt-get install --no-install-recommends debootstrap clang-15 lld-15";
@@ -442,8 +445,7 @@ const ci = {
                 "!./target/*/*.tar.gz",
               ].join("\n"),
               key: "never_saved",
-              "restore-keys":
-                "19-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-",
+              "restore-keys": cacheKeyPrefix,
             },
           },
           {
@@ -857,8 +859,7 @@ const ci = {
                 "!./target/*/*.zip",
                 "!./target/*/*.tar.gz",
               ].join("\n"),
-              key:
-                "18-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ github.sha }}",
+              key: cacheKeyPrefix + "${{ github.sha }}",
             },
           },
         ]),
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 61a2ac6b69f17e..fbffd8ba70c166 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -274,7 +274,7 @@ jobs:
             !./target/*/*.zip
             !./target/*/*.tar.gz
           key: never_saved
-          restore-keys: '19-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-'
+          restore-keys: '18-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-'
       - name: Apply and update mtime cache
         if: '!(github.event_name == ''pull_request'' && matrix.skip_pr) && (steps.exit_early.outputs.EXIT_EARLY != ''true'' && (!startsWith(github.ref, ''refs/tags/'')))'
         uses: ./.github/mtime_cache