diff --git a/README.md b/README.md
index 5362885..e720b13 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,10 @@
 
 ```bash
 pip install orb-models
+pip install "pynanoflann@git+https://github.com/dwastberg/pynanoflann#egg=af434039ae14bedcbb838a7808924d6689274168",
 ```
+Pynanoflann is not available on PyPI, so you must install it from the git repository.
+
 Orb models are expected to work on MacOS and Linux. Windows support is not guaranteed.
 
 ### Pretrained models
diff --git a/pyproject.toml b/pyproject.toml
index 1a8af00..eae038f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,6 @@ dependencies = [
     "torch==2.2.0",
     "ase==3.22.1",
     "dm-tree>=0.1.8",
-    "pynanoflann@git+https://github.com/dwastberg/pynanoflann#egg=af434039ae14bedcbb838a7808924d6689274168",
 ]
 
 [build-system]
@@ -40,4 +39,6 @@ Issues = "https://github.com/orbital-materials/orb-models/issues"
 CI = "https://github.com/orbital-materials/orb-models/actions"
 
 [project.optional-dependencies]
-test = ["pytest"]
\ No newline at end of file
+test = ["pytest", 
+    "pynanoflann@git+https://github.com/dwastberg/pynanoflann#egg=af434039ae14bedcbb838a7808924d6689274168",
+]
\ No newline at end of file