diff --git a/pyproject.toml b/pyproject.toml
index 3dafbc12..04aee89b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -42,7 +42,7 @@ Bug-tracker = "https://github.com/waltsims/k-wave-python/issues"
 [project.optional-dependencies]
 test = ["pytest", "phantominator"]
 example = ["gdown==4.7.1"]
-docs = ["m2r2~=0.3.3.post2",
+docs = ["m2r2==0.3.3",
     "sphinx-copybutton==0.5.2",
     "sphinx-tabs==3.4.4",
     "sphinx-toolbox==3.5.0",