diff --git a/plugins/tiddlywiki/aws/docs/help.tid b/plugins/tiddlywiki/aws/docs/help.tid
index 4ee6b5922..c6b294e07 100644
--- a/plugins/tiddlywiki/aws/docs/help.tid
+++ b/plugins/tiddlywiki/aws/docs/help.tid
@@ -43,14 +43,14 @@ Save a raw tiddler to a file in an S3 bucket.
 Save raw tiddlers matching a filter to an S3 bucket.
 
 ```
---aws s3-savetiddlers <filter> <region> <bucket> <filenamefilter> <savetype>
+--aws s3-savetiddlers <filter> <region> <bucket> <filenamefilter> <savetypefilter>
 ```
 
 * ''filter'': filter identifying tiddlers to render
 * ''region'': AWS region
 * ''bucket'': name of the bucket to save the files
 * ''filenamefilter'': filter for converting tiddler titles to filepaths (eg `[encodeuricomponent[]addprefix[files/]addsuffix[.html]]`)
-* ''savetype'': optional; the MIME type for the saved file (defaults to ''type'' or "text/html")
+* ''savetypefilter'': optional; a filter that is passed the title of the tiddler being saved and should yield the MIME type for the saved file (defaults to a filter that yields the value of the ''type'' field)
 
 ! "s3-rendertiddler" subcommand
 
@@ -74,7 +74,7 @@ Save the results of rendering a tiddler to a file in an S3 bucket.
 Save the results of rendering tiddlers identified by a filter to files in an S3 bucket.
 
 ```
---aws s3-rendertiddlers <filter> <template> <region> <bucket> <filenamefilter> <type> <savetype>
+--aws s3-rendertiddlers <filter> <template> <region> <bucket> <filenamefilter> <type> <savetypefilter>
 ```
 
 * ''filter'': filter identifying tiddlers to render
@@ -83,4 +83,4 @@ Save the results of rendering tiddlers identified by a filter to files in an S3
 * ''bucket'': name of the bucket to save the rendered file
 * ''filenamefilter'': filter for converting tiddler titles to filepaths (eg `[encodeuricomponent[]addprefix[files/]addsuffix[.html]]`)
 * ''type'': optional render type (defaults to "text/html")
-* ''savetype'': optional; the MIME type for the saved file (defaults to ''type'' or "text/html")
+* ''savetypefilter'': optional; a filter that is passed the title of the tiddler being rendered and should yield the MIME type for the saved file (defaults to the value of the ''type'' field via `[is[tiddler]get[type]]`)
diff --git a/plugins/tiddlywiki/aws/modules/command.js b/plugins/tiddlywiki/aws/modules/command.js
index 19829cc35..7b9b95b2e 100644
--- a/plugins/tiddlywiki/aws/modules/command.js
+++ b/plugins/tiddlywiki/aws/modules/command.js
@@ -129,7 +129,7 @@ Command.prototype.subCommands["s3-rendertiddlers"] = function() {
 		bucket = this.params[4],
 		filenameFilter = this.params[5],
 		type = this.params[6] || "text/html",
-		saveType = this.params[7] || type,
+		saveTypeFilter = this.params[7] || "[[" + type + "]]",
 		tiddlers = wiki.filterTiddlers(filter);
 	// Check parameters
 	if(!filter || !template || !region || !bucket || !filenameFilter) {
@@ -139,14 +139,13 @@ Command.prototype.subCommands["s3-rendertiddlers"] = function() {
 		tiddlers,
 		20,
 		function(title,callback) {
-			var parser = wiki.parseTiddler(template),
+			var parser = wiki.parseTiddler(template || title),
 				widgetNode = wiki.makeWidget(parser,{variables: {currentTiddler: title}}),
 				container = $tw.fakeDocument.createElement("div");
 			widgetNode.render(container,null);
 			var text = type === "text/html" ? container.innerHTML : container.textContent,
-				filename = wiki.filterTiddlers(filenameFilter,$tw.rootWidget,function(iterator) {
-					iterator(wiki.getTiddler(title),title)
-				})[0];
+				filename = wiki.filterTiddlers(filenameFilter,$tw.rootWidget,wiki.makeTiddlerIterator([title]))[0],
+				saveType = wiki.filterTiddlers(saveTypeFilter,$tw.rootWidget,wiki.makeTiddlerIterator([title]))[0];
 			awsUtils.putFile(region,bucket,filename,text,saveType,callback);
 		},
 		function(err,results) {
@@ -201,7 +200,7 @@ Command.prototype.subCommands["s3-savetiddlers"] = function() {
 		region = this.params[2],
 		bucket = this.params[3],
 		filenameFilter = this.params[4],
-		saveType = this.params[5],
+		saveTypeFilter = this.params[5] || "[is[tiddler]get[type]]",
 		tiddlers = wiki.filterTiddlers(filter);
 	// Check parameters
 	if(!filter || !region || !bucket || !filenameFilter) {
@@ -214,9 +213,8 @@ Command.prototype.subCommands["s3-savetiddlers"] = function() {
 			var tiddler = wiki.getTiddler(title),
 				text = tiddler.fields.text || "",
 				type = tiddler.fields.type || "text/vnd.tiddlywiki",
-				filename = wiki.filterTiddlers(filenameFilter,$tw.rootWidget,function(iterator) {
-					iterator(wiki.getTiddler(title),title)
-				})[0];
+				filename = wiki.filterTiddlers(filenameFilter,$tw.rootWidget,wiki.makeTiddlerIterator([title]))[0],
+				saveType = wiki.filterTiddlers(saveTypeFilter,$tw.rootWidget,wiki.makeTiddlerIterator([title]))[0];
 			awsUtils.putFile(region,bucket,filename,text,saveType || type,callback);
 		},
 		function(err,results) {