diff --git a/pyproject.toml b/pyproject.toml
index 8d59817..43f86d1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,7 +20,6 @@ dependencies = [
     "numpy>=1.24.0",
     "scipy>=1.9.3",
     "tqdm",
-    "pytest",
     "stim",
     "sinter>=1.12.0",
     "pymatching"
@@ -33,3 +32,6 @@ Documentation = "https://software.roffe.eu/ldpc"
 [tool.setuptools.packages.find]
 where = ["src_python"]  
 include = ["ldpc","ldpc.*"]
+
+[project.optional-dependencies]
+dev = ["pytest"]