diff --git a/core/modules/syncer.js b/core/modules/syncer.js
index 420e7cea9..45538e306 100644
--- a/core/modules/syncer.js
+++ b/core/modules/syncer.js
@@ -400,7 +400,7 @@ Syncer.prototype.handleLoginEvent = function() {
 	var self = this;
 	this.getStatus(function(err,isLoggedIn,username) {
 		if(!err && !isLoggedIn) {
-			$tw.passwordPrompt.createPrompt({
+			var promptInfo = $tw.passwordPrompt.createPrompt({
 				serviceName: $tw.language.getString("LoginToTiddlySpace"),
 				callback: function(data) {
 					self.login(data.username,data.password,function(err,isLoggedIn) {
@@ -409,6 +409,10 @@ Syncer.prototype.handleLoginEvent = function() {
 					return true; // Get rid of the password prompt
 				}
 			});
+			// Let the sync adaptor adjust the prompt
+			if(self.syncadaptor && self.syncadaptor.customiseLoginPrompt) {
+				self.syncadaptor.customiseLoginPrompt(promptInfo);
+			}
 		}
 	});
 };
diff --git a/editions/dev/tiddlers/from tw5.com/moduletypes/SyncAdaptorModules.tid b/editions/dev/tiddlers/from tw5.com/moduletypes/SyncAdaptorModules.tid
index a727991a8..92f124623 100644
--- a/editions/dev/tiddlers/from tw5.com/moduletypes/SyncAdaptorModules.tid	
+++ b/editions/dev/tiddlers/from tw5.com/moduletypes/SyncAdaptorModules.tid	
@@ -1,5 +1,5 @@
 created: 20130825162100000
-modified: 20200113094126878
+modified: 20201014124049248
 tags: dev moduletypes
 title: SyncAdaptorModules
 type: text/vnd.tiddlywiki
@@ -80,6 +80,31 @@ Attempts to login to the server with specified credentials. This method is optio
 |password |Password |
 |callback |Callback function invoked with parameter `err` |
 
+!! `customiseLoginPrompt(promptInfo)`
+
+Provides an opportunity to customise the login prompt.
+
+|!Parameter |!Description |
+|promptInfo |The `promptInfo` object returned by `$tw.passwordPrompt.createPrompt()` |
+
+Here's an example of customising the login prompt to include a "forgotten password" button:
+
+```
+SyncAdaptor.prototype.customiseLoginPrompt = function(promptInfo) {
+	promptInfo.form.appendChild($tw.utils.domMaker("button",{
+		attributes: {type: "submit"},
+		text: "Forgot password",
+		eventListeners: [{
+				name: "click",
+				handlerFunction: function(event) {
+					promptInfo.owner.removePrompt(promptInfo);
+					alert("Forgot password");
+				}
+			}]
+	}));
+};
+```
+
 !! `logout(callback)`
 
 Attempts to logout of the server. This method is optional.