diff --git a/pandas/core/series.py b/pandas/core/series.py
index 318f3fee2756b..f1bc67810b788 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -166,6 +166,7 @@
         DtypeBackend,
         DtypeObj,
         FilePath,
+        Frequency,
         IgnoreRaise,
         IndexKeyFunc,
         IndexLabel,
@@ -5630,7 +5631,7 @@ def dropna(
 
     def to_timestamp(
         self,
-        freq=None,
+        freq: Frequency | None = None,
         how: Literal["s", "e", "start", "end"] = "start",
         copy: bool | None = None,
     ) -> Series:
@@ -5946,7 +5947,13 @@ def _flex_method(self, other, op, *, level=None, fill_value=None, axis: Axis = 0
             return op(self, other)
 
     @Appender(ops.make_flex_doc("eq", "series"))
-    def eq(self, other, level=None, fill_value=None, axis: Axis = 0) -> Series:
+    def eq(
+        self,
+        other,
+        level: Level | None = None,
+        fill_value: float | None = None,
+        axis: Axis = 0,
+    ) -> Series:
         return self._flex_method(
             other, operator.eq, level=level, fill_value=fill_value, axis=axis
         )