diff --git a/src/draco/compression/point_cloud/algorithms/point_cloud_compression_method.h b/src/draco/compression/point_cloud/algorithms/point_cloud_compression_method.h
index 18307b57..9541c966 100644
--- a/src/draco/compression/point_cloud/algorithms/point_cloud_compression_method.h
+++ b/src/draco/compression/point_cloud/algorithms/point_cloud_compression_method.h
@@ -23,7 +23,7 @@ enum PointCloudCompressionMethod {
   // Generalized version of Encoding using the Octree method by Olivier
   // Devillers to d dimensions.
   // "Progressive lossless compression of arbitrary simplicial complexes"
-  // http://dx.doi.org/10.1145/566570.566591
+  // https://doi.org/10.1145/566570.566591
   KDTREE = 1,
   RESERVED_POINT_CLOUD_METHOD_2 = 2,  // Reserved for internal use.
   RESERVED_POINT_CLOUD_METHOD_3 = 0,  // Reserved for internal use.