diff --git a/src/mdevaluate/pbc.py b/src/mdevaluate/pbc.py
index b44f083..785d9d2 100644
--- a/src/mdevaluate/pbc.py
+++ b/src/mdevaluate/pbc.py
@@ -149,32 +149,21 @@ def nojump(frame: CoordinateFrame, usecache: bool = True) -> CoordinateFrame:
             i0 = 0
             delta = 0
 
-        delta = (
-            delta
-            + np.array(
-                np.vstack(
-                    [m[i0 : abstep + 1].sum(axis=0) for m in reader.nojump_matrices]
-                ).T
-            )
-            @ frame.box
-        )
+        delta = (delta
+            + np.vstack(
+                [m[i0 : abstep + 1].sum(axis=0) for m in reader.nojump_matrices]
+            ).T)
 
         reader._nojump_cache[abstep] = delta
         while len(reader._nojump_cache) > NOJUMP_CACHESIZE:
             reader._nojump_cache.popitem(last=False)
-        delta = delta[selection, :]
     else:
-        delta = (
-            np.array(
-                np.vstack(
-                    [
-                        m[: frame.step + 1, selection].sum(axis=0)
-                        for m in reader.nojump_matrices
-                    ]
+        delta = np.vstack(
+                [m[: frame.step + 1, selection].sum(axis=0) for m in reader.nojump_matrices]
                 ).T
-            )
-            @ frame.box
-        )
+    
+    delta = delta[selection, :]
+    delta = np.array(delta @ frame.box)
     return frame - delta