diff --git a/include/mitsuba/render/trimesh.h b/include/mitsuba/render/trimesh.h
index fb256d17..1ddac72c 100644
--- a/include/mitsuba/render/trimesh.h
+++ b/include/mitsuba/render/trimesh.h
@@ -54,6 +54,7 @@ struct TangentSpace {
 
 /** \brief Abstract triangle mesh base class
  * \ingroup librender
+ e \ingroup libpython
  */
 class MTS_EXPORT_RENDER TriMesh : public Shape {
 public:
diff --git a/src/libpython/render.cpp b/src/libpython/render.cpp
index 8079405b..e70434b8 100644
--- a/src/libpython/render.cpp
+++ b/src/libpython/render.cpp
@@ -211,6 +211,25 @@ void export_render() {
 		.def("getPrimitiveCount", &Shape::getPrimitiveCount)
 		.def("getEffectivePrimitiveCount", &Shape::getEffectivePrimitiveCount);
 
+	void (TriMesh::*triMesh_serialize1)(Stream *stream) const = &TriMesh::serialize;
+	void (TriMesh::*triMesh_serialize2)(Stream *stream, InstanceManager *) const = &TriMesh::serialize;
+
+	BP_CLASS(TriMesh, Shape, (bp::init<std::string, size_t, size_t, bool, bool, bool, bool, bool>()))
+		.def(bp::init<Stream *, InstanceManager *>())
+		.def(bp::init<Stream *, int>())
+		.def("getTriangleCount", &TriMesh::getTriangleCount)
+		.def("getVertexCount", &TriMesh::getVertexCount)
+		.def("hasVertexNormals", &TriMesh::hasVertexNormals)
+		.def("hasVertexColors", &TriMesh::hasVertexColors)
+		.def("hasVertexTexcoords", &TriMesh::hasVertexTexcoords)
+		.def("hasUVTangents", &TriMesh::hasUVTangents)
+		.def("computeUVTangents", &TriMesh::computeUVTangents)
+		.def("computeNormals", &TriMesh::computeNormals)
+		.def("rebuildTopology", &TriMesh::rebuildTopology)
+		.def("serialize", triMesh_serialize1)
+		.def("serialize", triMesh_serialize2)
+		.def("writeOBJ", &TriMesh::writeOBJ);
+
 	BP_STRUCT(BSDFSamplingRecord, (bp::init<const Intersection &, Sampler *, ETransportMode>()))
 		.def(bp::init<const Intersection &, const Vector &, ETransportMode>())
 		.def(bp::init<const Intersection &, const Vector &, const Vector &, ETransportMode>())
diff --git a/src/librender/trimesh.cpp b/src/librender/trimesh.cpp
index a32bd3ac..7a85e25f 100644
--- a/src/librender/trimesh.cpp
+++ b/src/librender/trimesh.cpp
@@ -818,9 +818,10 @@ void TriMesh::writeOBJ(const fs::path &path) const {
 	}
 
 	for (size_t i=0; i<m_triangleCount; ++i) {
-		int i0 = m_triangles[i].idx[0] + 1,
-			i1 = m_triangles[i].idx[1] + 1,
-			i2 = m_triangles[i].idx[2] + 1;
+		uint32_t i0 = m_triangles[i].idx[0] + 1,
+		         i1 = m_triangles[i].idx[1] + 1,
+		         i2 = m_triangles[i].idx[2] + 1;
+
 		if (m_normals && m_texcoords) {
 			os << "f " << i0 << "/" << i0 << "/" << i0 << " "
 			   <<  i1 << "/" << i1 << "/" << i1 << " "