diff --git a/IkiWiki/Plugin/osm.pm b/IkiWiki/Plugin/osm.pm
index 0fd7ca400..e85d4be62 100644
--- a/IkiWiki/Plugin/osm.pm
+++ b/IkiWiki/Plugin/osm.pm
@@ -561,139 +561,9 @@ sub cgi($) {
 }
 
 sub embed_map_code() {
-	return <<EOF;
-<script src="http://www.openlayers.org/api/OpenLayers.js"></script>
-<script>
-// taken from http://stackoverflow.com/questions/901115/get-query-string-values-in-javascript
-var urlParams = {};
-(function () {
-	var e,
-	a = /\\+/g,  // Regex for replacing addition symbol with a space
-	r = /([^&=]+)=?([^&]*)/g,
-	d = function (s) { return decodeURIComponent(s.replace(a, " ")); },
-	q = window.location.search.substring(1);
-
-	while (e = r.exec(q))
-	urlParams[d(e[1])] = d(e[2]);
-})();
-
-function mapsetup(divname, options) {
-	div = document.getElementById(divname);
-	if (options.fullscreen) {
-		permalink = 'permalink';
-		div.style.top = 0;
-		div.style.left = 0;
-		div.style.position = 'absolute';
-		div.style.width = '100%';
-		div.style.height = '100%';
-	}
-	else {
-		div.style.height = options.height;
-		div.style.width = options.width;
-		div.style.float = options.float;
-		permalink = {base: options.href, title: "View larger map"};
-	}
-	map = new OpenLayers.Map(divname, {
-		controls: [
-			new OpenLayers.Control.Navigation(),
-			new OpenLayers.Control.ScaleLine(),
-			new OpenLayers.Control.Permalink(permalink)
-		],
-		displayProjection: new OpenLayers.Projection("EPSG:4326"),
-		numZoomLevels: 18
-	});
-
-
-	map.addLayer(new OpenLayers.Layer.OSM());
-	if (options.format == 'CSV') {
-		pois = new OpenLayers.Layer.Text( "CSV",
-			{ location:"/" + options.map + "/pois.txt",
-			  projection: map.displayProjection
-			});
-	} else if (options.format == 'GeoJSON') {
-		pois = new OpenLayers.Layer.Vector("GeoJSON", {
-			protocol: new OpenLayers.Protocol.HTTP({
-				url: "/" + options.map + "/pois.json",
-				format: new OpenLayers.Format.GeoJSON()
-			}),
-			strategies: [new OpenLayers.Strategy.Fixed()]
-		});
-	} else {
-		pois = new OpenLayers.Layer.Vector("KML", {
-			protocol: new OpenLayers.Protocol.HTTP({
-				url: "/" + options.map + "/pois.kml",
-				format: new OpenLayers.Format.KML({
-					extractStyles: true,
-					extractAttributes: true
-				})
-			}),
-		strategies: [new OpenLayers.Strategy.Fixed()]});
-	}
-	map.addLayer(pois);
-	select = new OpenLayers.Control.SelectFeature(pois);
-	map.addControl(select);
-	select.activate();
-
-	pois.events.on({
-		"featureselected": function (event) {
-			var feature = event.feature;
-			var content = '<h2><a href="' + feature.attributes.href + '">' +feature.attributes.name + "</a></h2>" + feature.attributes.description;
-			popup = new OpenLayers.Popup.FramedCloud("chicken",
-				feature.geometry.getBounds().getCenterLonLat(),
-				new OpenLayers.Size(100,100),
-				content,
-				null, true, function () {select.unselectAll()});
-			feature.popup = popup;
-			map.addPopup(popup);
-		},
-		"featureunselected": function (event) {
-			var feature = event.feature;
-			if (feature.popup) {
-				map.removePopup(feature.popup);
-				feature.popup.destroy();
-				delete feature.popup;
-			}
-		}
-	});
-
-	if (options.editable) {
-		vlayer = new OpenLayers.Layer.Vector( "Editable" );
-		map.addControl(new OpenLayers.Control.EditingToolbar(vlayer));
-		map.addLayer(vlayer);
-	}
-
-	if (options.fullscreen) {
-		map.addControl(new OpenLayers.Control.PanZoomBar());
-		map.addControl(new OpenLayers.Control.LayerSwitcher({'ascending':false}));
-		map.addControl(new OpenLayers.Control.MousePosition());
-		map.addControl(new OpenLayers.Control.KeyboardDefaults());
-	} else {
-		map.addControl(new OpenLayers.Control.ZoomPanel());
-	}
-
-	//Set start centrepoint and zoom    
-	if (!options.lat || !options.lon) {
-		options.lat = urlParams['lat'];
-		options.lon = urlParams['lon'];
-	}
-	if (!options.zoom) {
-		options.zoom = urlParams['zoom'];
-	}
-	if (options.lat && options.lon) {
-		var lat = options.lat;
-		var lon = options.lon;
-		var zoom= options.zoom || 10;
-		center = new OpenLayers.LonLat( lon, lat ).transform(
-			new OpenLayers.Projection("EPSG:4326"), // transform from WGS 1984
-			map.getProjectionObject() // to Spherical Mercator Projection
-		);
-		map.setCenter (center, zoom);
-	} else {
-		pois.events.register("loadend", this, function () { map.zoomToExtent(pois.getDataExtent()); });
-	}
-}
-</script>
-EOF
+	return '<script src="http://www.openlayers.org/api/OpenLayers.js" type="text/javascript" charset="utf-8"></script>'.
+		'<script src="'.urlto("ikiwiki/osm.js", $from).
+		'" type="text/javascript" charset="utf-8"></script>'."\n";
 }
 
 1;
diff --git a/underlays/osm/ikiwiki/javascript/osm.js b/underlays/osm/ikiwiki/javascript/osm.js
new file mode 100644
index 000000000..7994c62fc
--- /dev/null
+++ b/underlays/osm/ikiwiki/javascript/osm.js
@@ -0,0 +1,128 @@
+// taken from http://stackoverflow.com/questions/901115/get-query-string-values-in-javascript
+var urlParams = {};
+(function () {
+	var e,
+	a = /\\+/g,  // Regex for replacing addition symbol with a space
+	r = /([^&=]+)=?([^&]*)/g,
+	d = function (s) { return decodeURIComponent(s.replace(a, " ")); },
+	q = window.location.search.substring(1);
+
+	while (e = r.exec(q))
+	urlParams[d(e[1])] = d(e[2]);
+})();
+
+function mapsetup(divname, options) {
+	div = document.getElementById(divname);
+	if (options.fullscreen) {
+		permalink = 'permalink';
+		div.style.top = 0;
+		div.style.left = 0;
+		div.style.position = 'absolute';
+		div.style.width = '100%';
+		div.style.height = '100%';
+	}
+	else {
+		div.style.height = options.height;
+		div.style.width = options.width;
+		div.style.float = options.float;
+		permalink = {base: options.href, title: "View larger map"};
+	}
+	map = new OpenLayers.Map(divname, {
+		controls: [
+			new OpenLayers.Control.Navigation(),
+			new OpenLayers.Control.ScaleLine(),
+			new OpenLayers.Control.Permalink(permalink)
+		],
+		displayProjection: new OpenLayers.Projection("EPSG:4326"),
+		numZoomLevels: 18
+	});
+
+
+	map.addLayer(new OpenLayers.Layer.OSM());
+	if (options.format == 'CSV') {
+		pois = new OpenLayers.Layer.Text( "CSV",
+			{ location:"/" + options.map + "/pois.txt",
+			  projection: map.displayProjection
+			});
+	} else if (options.format == 'GeoJSON') {
+		pois = new OpenLayers.Layer.Vector("GeoJSON", {
+			protocol: new OpenLayers.Protocol.HTTP({
+				url: "/" + options.map + "/pois.json",
+				format: new OpenLayers.Format.GeoJSON()
+			}),
+			strategies: [new OpenLayers.Strategy.Fixed()]
+		});
+	} else {
+		pois = new OpenLayers.Layer.Vector("KML", {
+			protocol: new OpenLayers.Protocol.HTTP({
+				url: "/" + options.map + "/pois.kml",
+				format: new OpenLayers.Format.KML({
+					extractStyles: true,
+					extractAttributes: true
+				})
+			}),
+		strategies: [new OpenLayers.Strategy.Fixed()]});
+	}
+	map.addLayer(pois);
+	select = new OpenLayers.Control.SelectFeature(pois);
+	map.addControl(select);
+	select.activate();
+
+	pois.events.on({
+		"featureselected": function (event) {
+			var feature = event.feature;
+			var content = '<h2><a href="' + feature.attributes.href + '">' +feature.attributes.name + "</a></h2>" + feature.attributes.description;
+			popup = new OpenLayers.Popup.FramedCloud("chicken",
+				feature.geometry.getBounds().getCenterLonLat(),
+				new OpenLayers.Size(100,100),
+				content,
+				null, true, function () {select.unselectAll()});
+			feature.popup = popup;
+			map.addPopup(popup);
+		},
+		"featureunselected": function (event) {
+			var feature = event.feature;
+			if (feature.popup) {
+				map.removePopup(feature.popup);
+				feature.popup.destroy();
+				delete feature.popup;
+			}
+		}
+	});
+
+	if (options.editable) {
+		vlayer = new OpenLayers.Layer.Vector( "Editable" );
+		map.addControl(new OpenLayers.Control.EditingToolbar(vlayer));
+		map.addLayer(vlayer);
+	}
+
+	if (options.fullscreen) {
+		map.addControl(new OpenLayers.Control.PanZoomBar());
+		map.addControl(new OpenLayers.Control.LayerSwitcher({'ascending':false}));
+		map.addControl(new OpenLayers.Control.MousePosition());
+		map.addControl(new OpenLayers.Control.KeyboardDefaults());
+	} else {
+		map.addControl(new OpenLayers.Control.ZoomPanel());
+	}
+
+	//Set start centrepoint and zoom    
+	if (!options.lat || !options.lon) {
+		options.lat = urlParams['lat'];
+		options.lon = urlParams['lon'];
+	}
+	if (!options.zoom) {
+		options.zoom = urlParams['zoom'];
+	}
+	if (options.lat && options.lon) {
+		var lat = options.lat;
+		var lon = options.lon;
+		var zoom= options.zoom || 10;
+		center = new OpenLayers.LonLat( lon, lat ).transform(
+			new OpenLayers.Projection("EPSG:4326"), // transform from WGS 1984
+			map.getProjectionObject() // to Spherical Mercator Projection
+		);
+		map.setCenter (center, zoom);
+	} else {
+		pois.events.register("loadend", this, function () { map.zoomToExtent(pois.getDataExtent()); });
+	}
+}