diff --git a/.forgejo/workflows/ci.yaml b/.forgejo/workflows/ci.yaml
index daaafd6..0c5d79a 100644
--- a/.forgejo/workflows/ci.yaml
+++ b/.forgejo/workflows/ci.yaml
@@ -99,7 +99,7 @@ jobs:
           VERSION: ${{ steps.meta.outputs.version }}
         run: |
           set -eu
-          yq '."build-options".env.CRAFTER_BUILD_VERSION = strenv(VERSION)' "$MANIFEST" > "$CI_MANIFEST"
+          yq '(.modules[] | select(.name == "crafter-build") | ."build-options".env.CRAFTER_BUILD_VERSION) = strenv(VERSION)' "$MANIFEST" > "$CI_MANIFEST"
           grep -n 'CRAFTER_BUILD_VERSION' "$CI_MANIFEST"
           flatpak-builder --force-clean --ccache --disable-rofiles-fuse \
             --state-dir=/root/.cache/flatpak-builder \
diff --git a/packaging/flatpak/net.catcrafts.CrafterBuild.yaml b/packaging/flatpak/net.catcrafts.CrafterBuild.yaml
index a8b769a..9eeb64f 100644
--- a/packaging/flatpak/net.catcrafts.CrafterBuild.yaml
+++ b/packaging/flatpak/net.catcrafts.CrafterBuild.yaml
@@ -28,15 +28,6 @@ finish-args:
   # gdb and friends from the Sdk
   - --allow=devel
   - --env=PATH=/app/bin:/usr/bin
-build-options:
-  env:
-    CRAFTER_BUILD_LLVM_DIR: /app
-    # The shipped binary runs on any x86_64 from the last decade; user
-    # projects still build with -march=native by default.
-    CRAFTER_BUILD_MARCH: x86-64-v2
-    CRAFTER_BUILD_MTUNE: generic
-    # CI replaces this with the tag; a local build is a development build.
-    CRAFTER_BUILD_VERSION: 0.0.0-dev
 cleanup:
   - /share/man
   - /share/doc
@@ -188,6 +179,18 @@ modules:
       # (sibling repos tracking their default branch, see AGENTS.md).
       build-args:
         - --share=network
+      # On this module, not at the top of the manifest: top-level build
+      # options are part of every module's cache key, and the version changes
+      # with every commit, which made flatpak-builder rebuild LLVM each run.
+      env:
+        CRAFTER_BUILD_LLVM_DIR: /app
+        # The shipped binary runs on any x86_64 from the last decade; user
+        # projects still build with -march=native by default.
+        CRAFTER_BUILD_MARCH: x86-64-v2
+        CRAFTER_BUILD_MTUNE: generic
+        # CI replaces this with the version; a local build is a development
+        # build.
+        CRAFTER_BUILD_VERSION: 0.0.0-dev
     build-commands:
       # Bootstrap by hand, then let the result build itself: only the
       # self-hosted binary has asset support and ThinLTO.