diff --git a/src/segy/arrays.py b/src/segy/arrays.py
index 92f9434..f491158 100644
--- a/src/segy/arrays.py
+++ b/src/segy/arrays.py
@@ -126,7 +126,7 @@ def __getitem__(self, item: Any) -> Any:  # noqa: ANN401
         if isinstance(item, str):
             item = self._normalize_and_validate_keys(item)
         elif isinstance(item, list) and all(isinstance(i, str) for i in item):
-            if all(key in item in self.dtype.names for key in item):
+            if all(key in self.dtype.names for key in item):
                 return super().__getitem__(item)
 
             item = self._normalize_and_validate_keys(item)
@@ -143,7 +143,7 @@ def __setitem__(self, key: Any, value: Any) -> None:  # noqa: ANN401
             key = self._normalize_and_validate_keys(key)
 
         elif isinstance(key, list) and all(isinstance(i, str) for i in key):
-            if all(k in key in self.dtype.names for k in key):
+            if all(k in self.dtype.names for k in key):
                 super().__setitem__(key, value)  # type: ignore[no-untyped-call]
                 return