diff --git a/.github/ci/build.sh b/.github/ci/build.sh
index ebd672a..fe6ac4d 100755
--- a/.github/ci/build.sh
+++ b/.github/ci/build.sh
@@ -19,8 +19,14 @@ git remote add upstream https://github.com/embassy-rs/stm32-data
 git fetch --depth 15 upstream main
 git clone --depth 1 --branch stm32-data-$(git merge-base HEAD upstream/main) https://github.com/embassy-rs/stm32-data-generated/ build
 
+# move the sources directory out of the cache if it exists
+mv /ci/cache/sources ./sources || true
+
 ./d ci
 
+# move the sources directory into the cache
+mv ./sources /ci/cache/sources
+
 # upload diff
 (
     cd build
diff --git a/d b/d
index 5457592..3ba3c08 100755
--- a/d
+++ b/d
@@ -4,6 +4,7 @@ set -e
 cd $(dirname $0)
 
 CMD=$1
+REV=7b078cef5335129b38245f0a7566103b9245973f
 shift
 
 case "$CMD" in
@@ -11,7 +12,7 @@ case "$CMD" in
         rm -rf ./sources/
         git clone https://github.com/embassy-rs/stm32-data-sources.git ./sources/
         cd ./sources/
-        git checkout 7b078cef5335129b38245f0a7566103b9245973f
+        git checkout $REV
     ;;
     install-chiptool)
         cargo install --git https://github.com/embassy-rs/chiptool
@@ -43,6 +44,10 @@ case "$CMD" in
     ;;
     ci)
         [ -d sources ] || ./d download-all
+        cd ./sources/
+        git fetch origin $REV
+        git checkout $REV
+        cd ..
         rm -rf build/{data,stm32-metapac}
         cargo run --release --bin stm32-data-gen
         cargo run --release --bin stm32-metapac-gen