diff --git a/.github/actions/cache-build/action.yml b/.github/actions/cache-build/action.yml
index a23692ef36..c118b59c88 100644
--- a/.github/actions/cache-build/action.yml
+++ b/.github/actions/cache-build/action.yml
@@ -11,17 +11,22 @@ runs:
       uses: buildjet/cache@v3
       id: cache-build
       env:
+        # WARN: Don't touch this cache key. Currently github.sha refers to the latest commit in main
+        # and not the branch that's attempting to merge to main, which causes CI errors when merged
+        # to main.
+        # TODO: Fix this problem if intending to modify this cache key.
         cache-name: prod-build
         key-1: ${{ inputs.node_version }}-${{ hashFiles('yarn.lock') }}
         key-2: ${{ hashFiles('apps/**/**.[jt]s', 'apps/**/**.[jt]sx', 'packages/**/**.[jt]s', 'packages/**/**.[jt]sx', '!**/node_modules') }}
-        key-3: ${{ github.sha }}
+        key-3: ${{ github.event.pull_request.number || github.ref }}
+        key-4: ${{ github.sha }}
       with:
         path: |
           ${{ github.workspace }}/apps/web/.next
           ${{ github.workspace }}/apps/web/public/embed
           **/.turbo/**
           **/dist/**
-        key: ${{ runner.os }}-${{ env.cache-name }}-${{ env.key-1 }}-${{ env.key-2 }}-${{ env.key-3 }}
+        key: ${{ runner.os }}-${{ env.cache-name }}-${{ env.key-1 }}-${{ env.key-2 }}-${{ env.key-3 }}-${{ env.key-4 }}
     - run: |
         export NODE_OPTIONS="--max_old_space_size=8192"
         yarn build