diff --git a/debian/changelog b/debian/changelog
index 6b819d201d..601036ef56 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+matrix-synapse-py3 (1.24.0+nmu1) UNRELEASED; urgency=medium
+
+  * Update dependencies to account for the removal of the transitional
+    dh-systemd package from Debian Bullseye.
+
+ -- Dan Callahan <danc@element.io>  Tue, 12 Jan 2021 12:08:33 +0000
+
 matrix-synapse-py3 (1.24.0) stable; urgency=medium
 
   * New synapse release 1.24.0.
diff --git a/debian/control b/debian/control
index bae14b41e4..b10401be43 100644
--- a/debian/control
+++ b/debian/control
@@ -3,9 +3,11 @@ Section: contrib/python
 Priority: extra
 Maintainer: Synapse Packaging team <packages@matrix.org>
 # keep this list in sync with the build dependencies in docker/Dockerfile-dhvirtualenv.
+# TODO: Remove the dependency on dh-systemd after dropping support for Ubuntu xenial
+#       On all other supported releases, it's merely a transitional package which
+#       does nothing but depends on debhelper (> 9.20160709)
 Build-Depends:
- debhelper (>= 9),
- dh-systemd,
+ debhelper (>= 9.20160709) | dh-systemd,
  dh-virtualenv (>= 1.1),
  libsystemd-dev,
  libpq-dev,
diff --git a/docker/Dockerfile-dhvirtualenv b/docker/Dockerfile-dhvirtualenv
index 2b7f01f7f7..e529293803 100644
--- a/docker/Dockerfile-dhvirtualenv
+++ b/docker/Dockerfile-dhvirtualenv
@@ -50,17 +50,22 @@ FROM ${distro}
 ARG distro=""
 ENV distro ${distro}
 
+# Python < 3.7 assumes LANG="C" means ASCII-only and throws on printing unicode
+# http://bugs.python.org/issue19846
+ENV LANG C.UTF-8
+
 # Install the build dependencies
 #
 # NB: keep this list in sync with the list of build-deps in debian/control
 # TODO: it would be nice to do that automatically.
+# TODO: Remove the dh-systemd stanza after dropping support for Ubuntu xenial
+#       it's a transitional package on all other, more recent releases
 RUN apt-get update -qq -o Acquire::Languages=none \
     && env DEBIAN_FRONTEND=noninteractive apt-get install \
         -yqq --no-install-recommends -o Dpkg::Options::=--force-unsafe-io \
         build-essential \
         debhelper \
         devscripts \
-        dh-systemd \
         libsystemd-dev \
         lsb-release \
         pkg-config \
@@ -70,7 +75,10 @@ RUN apt-get update -qq -o Acquire::Languages=none \
         python3-venv \
         sqlite3 \
         libpq-dev \
-        xmlsec1
+        xmlsec1 \
+    && ( env DEBIAN_FRONTEND=noninteractive apt-get install \
+         -yqq --no-install-recommends -o Dpkg::Options::=--force-unsafe-io \
+         dh-systemd || true )
 
 COPY --from=builder /dh-virtualenv_1.2~dev-1_all.deb /