diff --git a/manifests/builder.pp b/manifests/builder.pp
index 428a850..3e0d14b 100644
--- a/manifests/builder.pp
+++ b/manifests/builder.pp
@@ -37,8 +37,10 @@ class nodepool::builder(
   # This requires custom packages which aren't build for arm64; if we
   # ever have a need we can re-evaluate this.
   if ($::architecture == 'aarch64') {
+    $aarch64 = true
     $support_vhd = false
   } else {
+    $aarch64 = false
     $support_vhd = true
   }
 
diff --git a/templates/nodepool-builder.default.erb b/templates/nodepool-builder.default.erb
index 79a6c3e..2ea0e13 100644
--- a/templates/nodepool-builder.default.erb
+++ b/templates/nodepool-builder.default.erb
@@ -9,4 +9,8 @@ export <%= key %>='<%= @environment[key] %>'
 PIDFILE=/var/run/nodepool/nodepool-builder.pid
 <% end -%>
 DAEMON_ARGS="-c /etc/nodepool/nodepool.yaml -l /etc/nodepool/builder-logging.conf --build-workers <%= @build_workers %> --upload-workers <%= @upload_workers %>"
+<% if @aarch64 -%>
+export LD_PRELOAD=/usr/lib/aarch64-linux-gnu/libjemalloc.so.1
+<% else %>
 export LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libjemalloc.so.1
+<% end -%>