diff --git a/requirements_dev.txt b/requirements_dev.txt
index a161067..6aa1025 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -5,7 +5,7 @@ flake8==3.7.8
 h5py>=2.10.0
 igraph>=0.9.9
 louvain>=0.6.1
-matplotlib>=3.5.2
+matplotlib==3.5.2
 # numba requires numpy<21
 numpy>=1.18.3,<1.21
 pandas>=1.3.5