diff --git a/README.md b/README.md
index d83d73c..4a227c3 100644
--- a/README.md
+++ b/README.md
@@ -5,18 +5,22 @@ TetGen is a program to generate tetrahedral meshes of any 3D polyhedral domains.
 
 TetGen versions up to v1.6.0 have been developed by [Hang Si](https://github.com/sihang0592) during his affiliation with [Weierstrass Institute for Applied Analysis and Stochastics, (WIAS) Berlin](https://www.wias-berlin.de/software/tetgen).
 
+The primary development repository is [https://codeberg.org/TetGen/TetGen](https://codeberg.org/TetGen/TetGen). Please
+open any issues in this repository. The github repository [https://github.com/TetGen/Tetgen](https://github.com/TetGen/Tetgen)
+is a mirror of the codeberg repository.
+
 This repository provides the source code of the most recent versions of TetGen.
 The following releases are provided:
 
-- [v1.4.3, 2011](https://github.com/TetGen/TetGen/archive/refs/tags/v1.4.3.tar.gz): [MIT license with noncommercial clause](https://raw.githubusercontent.com/TetGen/TetGen/refs/tags/v1.4.3/LICENSE).
-- [v1.5.0, 2013](https://github.com/TetGen/TetGen/archive/refs/tags/v1.5.0.tar.gz): [AGPLv3 license](https://www.gnu.org/licenses/agpl-3.0.html).
-- [v1.5.1, 2018](https://github.com/TetGen/TetGen/archive/refs/tags/v1.5.1.tar.gz): [AGPLv3 license](https://www.gnu.org/licenses/agpl-3.0.html), recommended as most stable version.
-- [v1.6.0, 2020](https://github.com/TetGen/TetGen/archive/refs/tags/v1.6.0.tar.gz): [AGPLv3 license](https://www.gnu.org/licenses/agpl-3.0.html), most recent version with some rough edges.
+- [v1.4.3, 2011](https://codeberg.org/TetGen/TetGen/archive/refs/tags/v1.4.3.tar.gz): [MIT license with noncommercial clause](https://raw.githubusercontent.com/TetGen/TetGen/refs/tags/v1.4.3/LICENSE).
+- [v1.5.0, 2013](https://codeberg.org/TetGen/TetGen/archive/refs/tags/v1.5.0.tar.gz): [AGPLv3 license](https://www.gnu.org/licenses/agpl-3.0.html).
+- [v1.5.1, 2018](https://codeberg.org/TetGen/TetGen/archive/refs/tags/v1.5.1.tar.gz): [AGPLv3 license](https://www.gnu.org/licenses/agpl-3.0.html), recommended as most stable version.
+- [v1.6.0, 2020](https://codeberg.org/TetGen/TetGen/archive/refs/tags/v1.6.0.tar.gz): [AGPLv3 license](https://www.gnu.org/licenses/agpl-3.0.html), most recent version with some rough edges.
 
 It is planned to resume active development of TetGen and to publish future versions of TetGen via this repository.
 
 ## Documentation
-- Manuals are available in https://github.com/TetGen/Manuals.
+- Manuals are available in https://codeberg.org/TetGen/Manuals.
 - A technical paper about TetGen is available at [Hang Si, "TetGen, a Delaunay-Based Quality Tetrahedral Mesh Generator". ACM Trans. on Mathematical Software. 41 (2), 2015](http://doi.acm.org/10.1145/2629697)