diff --git a/requirements-dev.txt b/requirements-dev.txt
index 719c1e85..d945f85c 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -8,4 +8,5 @@ numpy>=1.26.0,<2.0.0
 cython>=3.0.2,<4.0.0
 robinson-foulds>=1.2,<2.0.0
 ete3>=3.1.3,<4.0.0
+dendropy>=4.6.1,<5.0.0
 git+https://github.com/althonos/pymuscle5