diff --git a/.gitea/workflows/docker.yaml b/.gitea/workflows/docker.yaml
index f68a950..133365a 100644
--- a/.gitea/workflows/docker.yaml
+++ b/.gitea/workflows/docker.yaml
@@ -30,7 +30,7 @@ jobs:
           docker buildx create --name ci-builder --driver docker-container --use || docker buildx use ci-builder
           docker buildx inspect --bootstrap
 
-      - name: Build and push image (with cache)
+      - name: Build and push image
         run: |
           docker buildx build \
             --pull \
diff --git a/Dockerfile b/Dockerfile
index 5bd226f..258814d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,6 +2,7 @@ FROM rocker/shiny:4.4.0
 
 # System dependencies commonly required by R packages
 RUN apt-get update && apt-get install -y \
+    curl \
     libcurl4-openssl-dev \
     libssl-dev \
     libxml2-dev \
@@ -22,7 +23,15 @@ COPY . /srv/shiny-server/
 
 # Prevent renv attempting to use pak
 ENV RENV_CONFIG_PAK_ENABLED=FALSE
-ENV CFLAGS=-Wno-error=format-security
+ENV RENV_DOWNLOAD_METHOD=libcurl
+
+# Some CRAN packages in this lockfile fail under Ubuntu hardening defaults
+# because -Werror=format-security turns benign warnings into build failures.
+RUN for f in /usr/local/lib/R/etc/Makeconf /usr/lib/R/etc/Makeconf; do \
+      if [ -f "$f" ]; then \
+        sed -i 's/-Werror=format-security/-Wno-error=format-security/g' "$f"; \
+      fi; \
+    done
 
 # Install renv and restore project packages
 RUN R --vanilla -e "install.packages('renv', repos='https://cran.rstudio.com')" && \
diff --git a/global.R b/global.R
index 1f456d0..60a5fb0 100644
--- a/global.R
+++ b/global.R
@@ -1,9 +1,7 @@
 library(plotly)
 library(shiny)
 library(shinyjs)
-library(htmlwidgets)
 library(tidyverse)
-library(DT)
 library(plm)
 library(lmtest)
 library(cluster)