diff --git a/src/geoJSONSource.js b/src/geoJSONSource.js
index 5f9c26e243e7159daf6b94801263bfeac2c96ba1..4c596c22d4db4eef501bd356d8931db086138a20 100644
--- a/src/geoJSONSource.js
+++ b/src/geoJSONSource.js
@@ -86,7 +86,7 @@ class GeoJSONSource extends Champlain.TileSource {
                 this.next_source.fill_tile(tile);
         });
 
-        Mainloop.idle_add(() => this._renderTile(tile));
+        Mainloop.idle_add(() => this._renderTile(tile), tile);
     }
 
     _validate([lon, lat]) {
diff --git a/src/gpxShapeLayer.js b/src/gpxShapeLayer.js
index 6154b82512fb493dcabe698fa185a03fa47cf726..e3a23b99f9e8cf63d0136f6e5da99814fefda91d 100644
--- a/src/gpxShapeLayer.js
+++ b/src/gpxShapeLayer.js
@@ -21,6 +21,7 @@ const GObject = imports.gi.GObject;
 
 const GeoJSONSource = imports.geoJSONSource;
 const ShapeLayer = imports.shapeLayer;
+const Utils = imports.utils;
 const Togeojson = imports.togeojson.togeojson;
 const Domparser = imports.xmldom.domparser;
 
@@ -37,7 +38,7 @@ class GpxShapeLayer extends ShapeLayer.ShapeLayer {
     }
 
     _parseContent() {
-        let s = this._fileContents.toString();
+        let s = Utils.getBufferText(this._fileContents);
         let parser = new Domparser.DOMParser();
         let json = Togeojson.toGeoJSON.gpx(parser.parseFromString(s));
         this._mapSource.parse(json);
diff --git a/src/kmlShapeLayer.js b/src/kmlShapeLayer.js
index ea13a7f4ccf9bb3ff93d4314be1fdbe6ce13c495..c7ef0a1ff1fe9e3b747a4a702f9ee1ae66c1f6d4 100644
--- a/src/kmlShapeLayer.js
+++ b/src/kmlShapeLayer.js
@@ -21,6 +21,7 @@ const GObject = imports.gi.GObject;
 
 const GeoJSONSource = imports.geoJSONSource;
 const ShapeLayer = imports.shapeLayer;
+const Utils = imports.utils;
 const Togeojson = imports.togeojson.togeojson;
 const Domparser = imports.xmldom.domparser;
 
@@ -36,7 +37,7 @@ class KmlShapeLayer extends ShapeLayer.ShapeLayer {
     }
 
     _parseContent() {
-        let s = this._fileContents.toString();
+        let s = Utils.getBufferText(this._fileContents);
         let parser = new Domparser.DOMParser();
         let json = Togeojson.toGeoJSON.kml(parser.parseFromString(s));
         this._mapSource.parse(json);