diff --git a/pkgs/development/python-modules/langchain-core/default.nix b/pkgs/development/python-modules/langchain-core/default.nix
index 2ae93d91c052..bd4bcc133901 100644
--- a/pkgs/development/python-modules/langchain-core/default.nix
+++ b/pkgs/development/python-modules/langchain-core/default.nix
@@ -50,7 +50,10 @@ buildPythonPackage rec {
 
   build-system = [ pdm-backend ];
 
-  pythonRelaxDeps = [ "tenacity" ];
+  pythonRelaxDeps = [
+    "packaging"
+    "tenacity"
+  ];
 
   dependencies = [
     jsonpatch