diff --git a/src/services/port.js b/src/services/port.js
index 559385644..bba42b7c7 100644
--- a/src/services/port.js
+++ b/src/services/port.js
@@ -6,7 +6,7 @@ const dataDir = require('./data_dir');
 function parseAndValidate(portStr, source) {
     const portNum = parseInt(portStr);
 
-    if (!portNum || portNum < 0 || portNum >= 65536) {
+    if (!portNum && portNum !== 0 || portNum < 0 || portNum >= 65536) {
         console.log(`FATAL ERROR: Invalid port value "${portStr}" from ${source}, should be a number between 0 and 65536.`);
         process.exit(-1);
     }
diff --git a/src/www b/src/www
index 778197e37..16989404b 100644
--- a/src/www
+++ b/src/www
@@ -100,7 +100,11 @@ async function startTrilium() {
      */
 
     httpServer.keepAliveTimeout = 120000 * 5;
-    httpServer.listen(port, host);
+    if (port !== 0) {
+      httpServer.listen(port, host); // TCP socket.
+    } else {
+      httpServer.listen(host); // Unix socket.
+    }
     httpServer.on('error', error => {
             if (error.syscall !== 'listen') {
                 throw error;