diff --git a/hosts/monitoring/prometheus.nix b/hosts/monitoring/prometheus.nix
index 0adb80b..96457cb 100644
--- a/hosts/monitoring/prometheus.nix
+++ b/hosts/monitoring/prometheus.nix
@@ -20,6 +20,7 @@
       {
         job_name = "synapse";
         scrape_interval = "15s";
+        scheme = "https";
         metrics_path = "/_synapse/metrics";
         static_configs = [{ targets = [ "matrix.berlin.ccc.de:443" ]; }];
       }