diff --git a/src/connection.ts b/src/connection.ts
index 4241efc85..d342dd419 100644
--- a/src/connection.ts
+++ b/src/connection.ts
@@ -1052,7 +1052,7 @@ class Connection extends EventEmitter {
       throw new TypeError('The "config" argument is required and must be of type Object.');
     }
 
-    if (typeof config.server !== 'string') {
+    if (typeof config.server !== 'string' && !config.options.connector) {
       throw new TypeError('The "config.server" property is required and must be of type string.');
     }
 
@@ -1900,7 +1900,7 @@ class Connection extends EventEmitter {
   initialiseConnection() {
     const signal = this.createConnectTimer();
 
-    if (this.config.options.port) {
+    if (this.config.options.port || this.config.options.connector) {
       return this.connectOnPort(this.config.options.port, this.config.options.multiSubnetFailover, signal, this.config.options.connector);
     } else {
       return instanceLookup({
diff --git a/test/unit/custom-connector.js b/test/unit/custom-connector.js
index 36e49d19d..fb23984bc 100644
--- a/test/unit/custom-connector.js
+++ b/test/unit/custom-connector.js
@@ -28,7 +28,6 @@ describe('custom connector', function() {
     const host = server.address().address;
     const port = server.address().port;
     const connection = new Connection({
-      server: host,
       options: {
         connector: async () => {
           customConnectorCalled = true;
@@ -37,7 +36,6 @@ describe('custom connector', function() {
             port,
           });
         },
-        port
       },
     });