diff --git a/.github/workflows/reproducible-builds.yml b/.github/workflows/reproducible-builds.yml
index b7dfae39f2..66bc18ed98 100644
--- a/.github/workflows/reproducible-builds.yml
+++ b/.github/workflows/reproducible-builds.yml
@@ -100,6 +100,12 @@ jobs:
         NODE_VERSION=$(cat .nvmrc)
         echo "version=$NODE_VERSION" >> $GITHUB_OUTPUT
 
+    - name: Get pnpm version for docker build arg
+      id: pnpm_version
+      run: |
+        PNPM_VERSION=$(grep -A 2 '^\s*pnpm:' pnpm-lock.yaml | grep 'version:' | awk '{print $2}')
+        echo "pnpm_version=$PNPM_VERSION" >> $GITHUB_OUTPUT
+
     - name: Set up docker Buildx
       uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3
     - name: Build docker image
@@ -115,6 +121,7 @@ jobs:
         build-args: |
           SOURCE_DATE_EPOCH=1
           NODE_VERSION=${{ steps.node_version.outputs.version }}
+          PNPM_VERSION=${{ steps.pnpm_version.outputs.pnpm_version }}
         cache-from: type=gha
         cache-to: type=gha,mode=max
 
diff --git a/reproducible-builds/Dockerfile b/reproducible-builds/Dockerfile
index 14d06fc4b1..470e8e5ae3 100644
--- a/reproducible-builds/Dockerfile
+++ b/reproducible-builds/Dockerfile
@@ -10,6 +10,7 @@ ENV SOURCE_DATE_EPOCH=1
 # Due to some issues with NVM reading .nvmrc, we define the version
 # as an environment variable and use that instead.
 ARG NODE_VERSION
+ARG PNPM_VERSION
 
 ENV SIGNAL_ENV=production
 
@@ -50,7 +51,7 @@ ENV PATH=$NVM_DIR/versions/node/v$NODE_VERSION/bin:$PATH
 ENV CI=true
 
 # Install pnpm
-RUN npm install -g pnpm@10.18.1
+RUN npm install -g pnpm@${PNPM_VERSION}
 
 RUN git config --global --add safe.directory /project
 
diff --git a/reproducible-builds/build.sh b/reproducible-builds/build.sh
index 47bab78d6b..35af74dc9d 100755
--- a/reproducible-builds/build.sh
+++ b/reproducible-builds/build.sh
@@ -18,7 +18,11 @@
 # all build dependencies at specific versions.
 # We set SOURCE_DATE_EPOCH to make system build timestamps deterministic.
 if [ -z "${SKIP_DOCKER_BUILD}" ]; then
-  docker build -t signal-desktop --build-arg SOURCE_DATE_EPOCH=1 --build-arg NODE_VERSION=$(cat ../.nvmrc) .
+  docker build -t signal-desktop \
+    --build-arg SOURCE_DATE_EPOCH=1 \
+    --build-arg NODE_VERSION="$(cat ../.nvmrc)" \
+    --build-arg PNPM_VERSION="$(grep -A 2 '^\s*pnpm:' ../pnpm-lock.yaml | grep 'version:' | awk '{print $2}')" \
+    .
 else
   echo "Skipping docker build step because SKIP_DOCKER_BUILD was set"
 fi
@@ -53,7 +57,7 @@ docker run --rm \
   --user "$(id -u):$(id -g)" \
   -e NPM_CONFIG_CACHE=/tmp/.npm-cache \
   -e PNPM_HOME=/tmp/.pnpm-home \
-  -e SOURCE_DATE_EPOCH=$source_date_epoch \
-  -e BUILD_TARGETS=$BUILD_TARGETS \
-  -e BUILD_ARCH=$BUILD_ARCH \
-  signal-desktop $1
+  -e SOURCE_DATE_EPOCH="$source_date_epoch" \
+  -e BUILD_TARGETS="$BUILD_TARGETS" \
+  -e BUILD_ARCH="$BUILD_ARCH" \
+  signal-desktop "$1"