diff --git a/flake.nix b/flake.nix
index 9c34223..55f73e0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -87,6 +87,18 @@
                 '';
               };
 
+              apiPort = lib.mkOption {
+                type = lib.types.port;
+                default = 9188;
+                description = "Port for the web/API server.";
+              };
+
+              transportPort = lib.mkOption {
+                type = lib.types.port;
+                default = 9187;
+                description = "Port for the TTP/QUIC transport server.";
+              };
+
               openFirewall = lib.mkOption {
                 type = lib.types.bool;
                 default = true;
@@ -125,6 +137,11 @@
                   Restart = "always";
                   RestartSec = "5s";
 
+                  Environment = [
+                    "API_PORT=${toString cfg.apiPort}"
+                    "OMIKRON_PORT=${toString cfg.transportPort}"
+                  ];
+
                   EnvironmentFile = cfg.environmentFiles;
 
                   AmbientCapabilities = [ "CAP_NET_BIND_SERVICE" ];
@@ -161,8 +178,8 @@
               };
 
               networking.firewall = lib.mkIf cfg.openFirewall {
-                allowedTCPPorts = [ 9187 9188 ];
-                allowedUDPPorts = [ 9187 9188 ];
+                allowedTCPPorts = [ cfg.transportPort cfg.apiPort ];
+                allowedUDPPorts = [ cfg.transportPort cfg.apiPort ];
               };
             };
           };
diff --git a/src/main.rs b/src/main.rs
index 8143c9f..7d5cfcc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -35,8 +35,13 @@ async fn main() {
     log_in!("Incoming messages");
     log_out!("Outgoing messages");
 
+    let omikron_port: u16 = env::var("OMIKRON_PORT")
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(9187);
+
     tokio::spawn(async move {
-        match omikron_connection::start(9187).await {
+        match omikron_connection::start(omikron_port).await {
             Err(e) => log_err!(0, PrintType::General, "{:?}", e),
             _ => {}
         }
@@ -59,7 +64,12 @@ async fn main() {
         log!("  Users");
     }
 
-    let _ = server::server::start(9188).await;
+    let api_port: u16 = env::var("API_PORT")
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or(9188);
+
+    let _ = server::server::start(api_port).await;
 
     tokio::signal::ctrl_c().await.unwrap();
 }