diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f8846ce6..77863a46 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -15,7 +15,9 @@ jobs:
 
     - name: Build fbpcf docker image
       run: |
-        ./build-docker.sh -u
+        # The "-d" flag builds the library with -Werror
+        # so we can catch warnings at diff time.
+        ./build-docker.sh -u -d
 
     - name: Sanity check fbpcf library
       timeout-minutes: 3
diff --git a/build-docker.sh b/build-docker.sh
index ea1531bb..71d26dc7 100755
--- a/build-docker.sh
+++ b/build-docker.sh
@@ -22,6 +22,7 @@ Usage: $PROG_NAME [-u] [-f] [-t TAG]
 
 -u: builds the docker images against ubuntu (default)
 -f: forces a rebuild of all docker image dependencies (even if they already exist)
+-d: whether to build in dev mode. This sets the -Werror flag during the cmake build.
 -t TAG: Use the specified tag for the built image (default: latest)
 EOF
   exit 1
@@ -32,7 +33,8 @@ OS_RELEASE="${UBUNTU_RELEASE}"
 DOCKER_EXTENSION=".ubuntu"
 FORCE_REBUILD=false
 TAG="latest"
-while getopts "u,f,t:" o; do
+DEV_MODE=false
+while getopts "u,f,d,t:" o; do
   case $o in
   u)
     IMAGE_PREFIX="ubuntu"
@@ -40,6 +42,7 @@ while getopts "u,f,t:" o; do
     DOCKER_EXTENSION=".ubuntu"
     ;;
   f) FORCE_REBUILD=true ;;
+  d) DEV_MODE=true ;;
   t) TAG=$OPTARG;;
   *) usage ;;
   esac
@@ -91,11 +94,17 @@ build_dep_image "${FOLLY_IMAGE}" "folly" "--build-arg os_release=${OS_RELEASE} -
 FOLLY_IMAGE="${RETURN}"
 
 printf "\nBuilding fbpcf/%s docker image...\n" ${IMAGE_PREFIX}
+CMAKE_FLAGS=""
+if [ "${DEV_MODE}" == true ]; then
+  printf "Using dev mode. Passing -Werror to cmake."
+  CMAKE_FLAGS="-Werror"
+fi
 docker build \
   --build-arg os_release="${OS_RELEASE}" \
   --build-arg emp_image="${EMP_IMAGE}" \
   --build-arg aws_image="${AWS_IMAGE}" \
   --build-arg folly_image="${FOLLY_IMAGE}" \
   --build-arg gcp_image="${GCP_IMAGE}" \
+  --build-arg cmake_flags="${CMAKE_FLAGS}" \
   --compress \
   -t "fbpcf/${IMAGE_PREFIX}:${TAG}" -f "docker/Dockerfile${DOCKER_EXTENSION}" .
diff --git a/docker/Dockerfile.ubuntu b/docker/Dockerfile.ubuntu
index 029a84df..52699810 100644
--- a/docker/Dockerfile.ubuntu
+++ b/docker/Dockerfile.ubuntu
@@ -8,6 +8,7 @@ ARG emp_image="fbpcf/ubuntu-emp:0.2.3"
 ARG aws_image="fbpcf/ubuntu-aws-s3-core:1.8.177"
 ARG folly_image="fbpcf/ubuntu-folly:2021.03.29.00"
 ARG gcp_image="fbpcf/ubuntu-gcp-cloud-cpp:1.32.1"
+ARG cmake_flags=""
 
 FROM ${emp_image} as emp
 FROM ${aws_image} as aws
@@ -57,7 +58,7 @@ COPY example/ ./example
 # Link all libraries post-install
 RUN ldconfig
 
-RUN cmake . -DTHREADING=ON -DEMP_USE_RANDOM_DEVICE=ON
+RUN cmake . -DTHREADING=ON -DEMP_USE_RANDOM_DEVICE=ON $cmake_flags
 RUN make && make install
 
 CMD ["/bin/bash"]