diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index cb9e53c..06c2a50 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -67,8 +67,8 @@ jobs:
     steps:
     - name: Install dependencies
       run: apt-get update && apt-get -y install curl git build-essential pkg-config libssl-dev lsb-release wget gnupg
-    - name: Install llvm 19
-      run: wget https://apt.llvm.org/llvm.sh && chmod +x llvm.sh && ./llvm.sh 19 && rm llvm.sh
+    - name: Install llvm 21
+      run: wget https://apt.llvm.org/llvm.sh && chmod +x llvm.sh && ./llvm.sh 21 && rm llvm.sh
     - uses: actions-rust-lang/setup-rust-toolchain@v1
       with:
         components: clippy
@@ -283,6 +283,7 @@ jobs:
           cargo generate --path . standalone-contract --name test-contract
           cd test-contract
           gmake build test check clippy
+          cargo clean
           cd ..
           cargo generate --path . workspace --name test-workspace
           cd test-workspace
diff --git a/standalone-contract/scripts/reproducible_build_docker b/standalone-contract/scripts/reproducible_build_docker
index dd61351..66e2899 100755
--- a/standalone-contract/scripts/reproducible_build_docker
+++ b/standalone-contract/scripts/reproducible_build_docker
@@ -55,9 +55,15 @@ else
   TASKS+=" build "
 fi
 
-$DOCKER run --rm $DOCKER_RUN_ARGS -v `pwd`:/code $DOCKER_IMAGE make $TASKS
+DOCKER_IMAGE_PLATFORM=linux/amd64
+if [[ "$(grep -E '^ID=' /etc/os-release 2>/dev/null | cut -d= -f2 | tr -d '"')" == "ubuntu" ]] && [[ "$(uname -m)" == "aarch64" ]]; then
+  echo "Ubuntu ARM64 detected. Using docker image with linux/arm64 platform. Note: This may produce different binaries than the default linux/amd64."
+  DOCKER_IMAGE_PLATFORM=linux/arm64
+fi
+
+$DOCKER run --platform=${DOCKER_IMAGE_PLATFORM} --rm $DOCKER_RUN_ARGS -v `pwd`:/code $DOCKER_IMAGE make $TASKS
 # Reset file ownerships for all files docker might touch
-$DOCKER run --rm $DOCKER_RUN_ARGS -e UID=`id -u` -e GID=`id -g` -v `pwd`:/code $DOCKER_IMAGE bash -c 'chown -R -f $UID:$GID checksums.txt build target'
+$DOCKER run --platform=${DOCKER_IMAGE_PLATFORM} --rm $DOCKER_RUN_ARGS -e UID=`id -u` -e GID=`id -g` -v `pwd`:/code $DOCKER_IMAGE bash -c 'chown -R -f $UID:$GID checksums.txt build target'
 
 if [[ "${UPDATE}" = "yes" ]]; then
   echo "${CHECKSUM_FILE_PATH} file is updated with latest binary hashes!"
diff --git a/workspace/scripts/reproducible_build_docker b/workspace/scripts/reproducible_build_docker
index dd61351..66e2899 100755
--- a/workspace/scripts/reproducible_build_docker
+++ b/workspace/scripts/reproducible_build_docker
@@ -55,9 +55,15 @@ else
   TASKS+=" build "
 fi
 
-$DOCKER run --rm $DOCKER_RUN_ARGS -v `pwd`:/code $DOCKER_IMAGE make $TASKS
+DOCKER_IMAGE_PLATFORM=linux/amd64
+if [[ "$(grep -E '^ID=' /etc/os-release 2>/dev/null | cut -d= -f2 | tr -d '"')" == "ubuntu" ]] && [[ "$(uname -m)" == "aarch64" ]]; then
+  echo "Ubuntu ARM64 detected. Using docker image with linux/arm64 platform. Note: This may produce different binaries than the default linux/amd64."
+  DOCKER_IMAGE_PLATFORM=linux/arm64
+fi
+
+$DOCKER run --platform=${DOCKER_IMAGE_PLATFORM} --rm $DOCKER_RUN_ARGS -v `pwd`:/code $DOCKER_IMAGE make $TASKS
 # Reset file ownerships for all files docker might touch
-$DOCKER run --rm $DOCKER_RUN_ARGS -e UID=`id -u` -e GID=`id -g` -v `pwd`:/code $DOCKER_IMAGE bash -c 'chown -R -f $UID:$GID checksums.txt build target'
+$DOCKER run --platform=${DOCKER_IMAGE_PLATFORM} --rm $DOCKER_RUN_ARGS -e UID=`id -u` -e GID=`id -g` -v `pwd`:/code $DOCKER_IMAGE bash -c 'chown -R -f $UID:$GID checksums.txt build target'
 
 if [[ "${UPDATE}" = "yes" ]]; then
   echo "${CHECKSUM_FILE_PATH} file is updated with latest binary hashes!"