diff --git a/tox.ini b/tox.ini
index 774cc0f9..47bbf80d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -26,7 +26,7 @@ deps =
     mpl32: matplotlib==3.2.*
     mpl33: matplotlib==3.3.*
     mpl34: matplotlib==3.4.*
-    mpl35: matplotlib==3.5.*
+    mpl35: matplotlib==3.5.1
     mpldev: git+https://github.com/matplotlib/matplotlib.git#egg=matplotlib
 extras =
     test