diff --git a/pyproject.toml b/pyproject.toml
index dfe86cf6..91fc5cd1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,7 +16,7 @@ description = "One line description of your module"
 dependencies = [
     "gemmi",
     "loguru",
-    "pydantic=2.6.0",
+    "pydantic==2.6.0",
     "networkx",
     "numpy",
     "rich",