diff --git a/src/particle/particle/particle.py b/src/particle/particle/particle.py
index 211b7ba7..f41c7f9d 100644
--- a/src/particle/particle/particle.py
+++ b/src/particle/particle/particle.py
@@ -71,6 +71,7 @@ class InvalidParticle(RuntimeError):
     _PREFERRED_PDGID[pdgid1] = sign * min(abs(pdgid1), abs(pdgid2))
     _PREFERRED_PDGID[pdgid2] = _PREFERRED_PDGID[pdgid1]
 
+
 def _isospin_converter(isospin: str) -> float | None:
     vals: dict[str | None, float | None] = {
         "0": 0.0,