diff --git a/src/pymatgen/core/trajectory.py b/src/pymatgen/core/trajectory.py
index 8284bf8c57c..eddc7c7d179 100644
--- a/src/pymatgen/core/trajectory.py
+++ b/src/pymatgen/core/trajectory.py
@@ -116,8 +116,7 @@ def __init__(
 
         if len(species) != coords.shape[1]:
             raise ValueError(
-                f"species (N={len(species)}) and coords "
-                f"(N={coords.shape[1]}) must have the same number of sites!"
+                f"species (N={len(species)}) and coords " f"(N={coords.shape[1]}) must have the same number of sites!"
             )
 
         if coords.shape[2] != 3: