diff --git a/conda_smithy/templates/run_docker_build.tmpl b/conda_smithy/templates/run_docker_build.tmpl
index 1a2d67860..e8390a0e1 100644
--- a/conda_smithy/templates/run_docker_build.tmpl
+++ b/conda_smithy/templates/run_docker_build.tmpl
@@ -25,12 +25,14 @@ show_channel_urls: true
 CONDARC
 )
 
+rm -f "$FEEDSTOCK_ROOT/build_artefacts/conda-forge-build-done"
+
 cat << EOF | docker run -i \
                         -v "${RECIPE_ROOT}":/recipe_root \
                         -v "${FEEDSTOCK_ROOT}":/feedstock_root \
                         -a stdin -a stdout -a stderr \
                         {{ docker.image }} \
-                        {{ docker.command }} || exit $?
+                        {{ docker.command }} || exit 1
 
 export BINSTAR_TOKEN=${BINSTAR_TOKEN}
 export PYTHONUNBUFFERED=1
@@ -50,5 +52,11 @@ conda build /recipe_root --quiet || exit 1
 {%- endfor -%}
 {%- endblock -%}
 
+touch /feedstock_root/build_artefacts/conda-forge-build-done
 EOF
 
+# double-check that the build got to the end
+# see https://github.com/conda-forge/conda-smithy/pull/337
+# for a possible fix
+set -x
+test -f "$FEEDSTOCK_ROOT/build_artefacts/conda-forge-build-done" || exit 1