diff --git a/Containerfile b/Containerfile
index 7cf6eff50f..5116308a0f 100644
--- a/Containerfile
+++ b/Containerfile
@@ -13,24 +13,18 @@ ARG RECIPE
 # See issue #28 (https://github.com/ublue-os/startingpoint/issues/28).
 COPY usr /usr
 
-# Copy recipe.
+# Copy the recipe that we're building.
 COPY ${RECIPE} /usr/share/ublue-os/recipe.yml
 
-# "yq" used in build.sh and the setup-flatpaks recipe to read the recipe.yml.
+# "yq" used in build.sh and the "setup-flatpaks" just-action to read recipe.yml.
 # Copied from the official container image since it's not available as an RPM.
 COPY --from=docker.io/mikefarah/yq /usr/bin/yq /usr/bin/yq
 
-# Copy scripts.
-RUN mkdir /tmp/scripts
+# Copy the build script and all custom scripts.
 COPY scripts /tmp/scripts
-RUN find /tmp/scripts -type f -exec chmod +x {} \;
 
-# Copy and run the build script.
-COPY build.sh /tmp/build.sh
-RUN chmod +x /tmp/build.sh && /tmp/build.sh
-
-# Clean up and finalize container build.
-RUN rm -rf \
-        /tmp/* \
-        /var/* && \
-    ostree container commit
+# Run the build script, then clean up temp files and finalize container build.
+RUN chmod +x /tmp/scripts/build.sh && \
+        /tmp/scripts/build.sh && \
+        rm -rf /tmp/* /var/* && \
+        ostree container commit
diff --git a/build.sh b/scripts/build.sh
similarity index 97%
rename from build.sh
rename to scripts/build.sh
index addf5436f4..f4a41c001a 100644
--- a/build.sh
+++ b/scripts/build.sh
@@ -33,6 +33,9 @@ if [[ ${#repos[@]} -gt 0 ]]; then
     echo "---"
 fi
 
+# Ensure that all script files are executable.
+find /tmp/scripts -type f -exec chmod +x {} \;
+
 # Run "pre" scripts.
 run_scripts() {
     script_mode="$1"