diff --git a/Dockerfile b/Dockerfile
index 928d46b..8cbb2f3 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,7 @@ COPY --from=portage /var/db/repos/gentoo /var/db/repos/gentoo
 
 # courier and pythonfilter install + activate + cleanup
 #RUN echo '=mail-filter/courier-pythonfilter-3.0.2-r1' > /etc/portage/package.accept_keywords && \
-RUN emerge mail-mta/courier mail-filter/courier-pythonfilter dev-python/pyspf
+RUN emerge mail-mta/courier mail-filter/courier-pythonfilter dev-python/pyspf dev-libs/libltdl
 RUN ln -s /usr/bin/pythonfilter /usr/libexec/filters && \
 	mkdir -p /etc/courier/filters/active && filterctl start pythonfilter && \
 	rm -rf /var/db/repos/gentoo