diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index fe40bc42887c4..cf81e6f173bdd 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -297,7 +297,9 @@ def trans(x):
     return result
 
 
-def maybe_cast_result(result, obj: "Series", numeric_only: bool = False, how: str = ""):
+def maybe_cast_result(
+    result: ArrayLike, obj: "Series", numeric_only: bool = False, how: str = ""
+) -> ArrayLike:
     """
     Try casting result to a different type if appropriate
 
@@ -320,19 +322,20 @@ def maybe_cast_result(result, obj: "Series", numeric_only: bool = False, how: st
     dtype = obj.dtype
     dtype = maybe_cast_result_dtype(dtype, how)
 
-    if not is_scalar(result):
-        if (
-            is_extension_array_dtype(dtype)
-            and not is_categorical_dtype(dtype)
-            and dtype.kind != "M"
-        ):
-            # We have to special case categorical so as not to upcast
-            # things like counts back to categorical
-            cls = dtype.construct_array_type()
-            result = maybe_cast_to_extension_array(cls, result, dtype=dtype)
+    assert not is_scalar(result)
+
+    if (
+        is_extension_array_dtype(dtype)
+        and not is_categorical_dtype(dtype)
+        and dtype.kind != "M"
+    ):
+        # We have to special case categorical so as not to upcast
+        # things like counts back to categorical
+        cls = dtype.construct_array_type()
+        result = maybe_cast_to_extension_array(cls, result, dtype=dtype)
 
-        elif numeric_only and is_numeric_dtype(dtype) or not numeric_only:
-            result = maybe_downcast_to_dtype(result, dtype)
+    elif numeric_only and is_numeric_dtype(dtype) or not numeric_only:
+        result = maybe_downcast_to_dtype(result, dtype)
 
     return result