diff --git a/CHANGES b/CHANGES
index a61bf7c08..802293499 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1697,4 +1697,5 @@
 * Fix issue where the icon for normal users was displayed incorrectly
 * Kill stuck backup processes after 12 hours and notify admins
 * Reconfigure email apps when mail domain is added/removed
+* Fix crash when only udp ports are defined
 
diff --git a/src/docker.js b/src/docker.js
index 29f40754c..5e61a13e7 100644
--- a/src/docker.js
+++ b/src/docker.js
@@ -180,7 +180,7 @@ function createSubcontainer(app, name, cmd, options, callback) {
     var portEnv = [];
     for (let portName in app.portBindings) {
         const hostPort = app.portBindings[portName];
-        const portType = portName in manifest.tcpPorts ? 'tcp' : 'udp';
+        const portType = (manifest.tcpPorts && portName in manifest.tcpPorts) ? 'tcp' : 'udp';
         const ports = portType == 'tcp' ? manifest.tcpPorts : manifest.udpPorts;
 
         var containerPort = ports[portName].containerPort || hostPort;