diff --git a/tests/ci_build/ci_build.sh b/tests/ci_build/ci_build.sh
index d5b0419f9..676613d9a 100755
--- a/tests/ci_build/ci_build.sh
+++ b/tests/ci_build/ci_build.sh
@@ -122,12 +122,22 @@ echo "Building container (${DOCKER_IMG_NAME})..."
 # If enviornment variable DOCKER_CACHE_REPO is set, use an external Docker repo for build caching
 if [[ -n "${DOCKER_CACHE_REPO}" ]]
 then
-    # Login for Docker registiry
+    # Login for Docker registry
     echo '$(python3 -m awscli ecr get-login --no-include-email --region us-west-2)'
     $(python3 -m awscli ecr get-login --no-include-email --region us-west-2)
-    echo "docker pull ${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME} || true"
-    docker pull "${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME}" || true
-    CACHE_FROM_CMD="--cache-from ${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME}"
+    # Pull pre-build container from Docker build cache,
+    # if one exists for the particular branch or pull request
+    echo "docker pull ${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME}"
+    if docker pull "${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME}"
+    then
+      CACHE_FROM_CMD="--cache-from ${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME}"
+    else
+      # If the build cache is empty of the particular branch or pull request,
+      # use the build cache associated with the master branch
+      echo "docker pull ${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:master"
+      docker pull "${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:master" || true
+      CACHE_FROM_CMD="--cache-from ${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:master"
+    fi
 else
     CACHE_FROM_CMD=''
 fi
@@ -152,6 +162,8 @@ fi
 # If enviornment variable DOCKER_CACHE_REPO is set, use an external Docker repo for build caching
 if [[ -n "${DOCKER_CACHE_REPO}" ]]
 then
+    # Push the container we just built to the Docker build cache
+    # that is associated with the particular branch or pull request
     echo "docker tag ${DOCKER_IMG_NAME} ${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME}"
     docker tag "${DOCKER_IMG_NAME}" "${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME}"
     echo "docker push ${DOCKER_CACHE_REPO}/${DOCKER_IMG_NAME}:${BRANCH_NAME}"