diff --git a/pyproject.toml b/pyproject.toml
index 2386ef12..67cd0b43 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,7 +40,7 @@ dev = [
     "coverage>=7.6.1,<8.0",
     # style/linting
     "ruff>=0.6.3,<1.0",
-    "mypy>=1.13,<1.18",
+    "mypy>=1.13,<1.20",
     "pandas-stubs>2.0,<3.0",
     # doc building
     "sphinx>=8.0,<8.2",
diff --git a/python/rateslib/data/fixings.py b/python/rateslib/data/fixings.py
index 0cfed727..eaa3bd29 100644
--- a/python/rateslib/data/fixings.py
+++ b/python/rateslib/data/fixings.py
@@ -2431,7 +2431,7 @@ def _maybe_get_rate_series_from_curve(
             return rate_series
 
 
-def _leg_fixings_to_list(rate_fixings: LegFixings, n_periods: int) -> list[PeriodFixings]:  # type: ignore[type-var]
+def _leg_fixings_to_list(rate_fixings: LegFixings, n_periods: int) -> list[PeriodFixings]:
     """Perform a conversion of 'LegRateFixings' into a list of PeriodFixings."""
     if isinstance(rate_fixings, NoInput):
         # NoInput is converted to a list of NoInputs
diff --git a/python/rateslib/instruments/bonds/float_rate_note.py b/python/rateslib/instruments/bonds/float_rate_note.py
index 755c6f87..b9abc992 100644
--- a/python/rateslib/instruments/bonds/float_rate_note.py
+++ b/python/rateslib/instruments/bonds/float_rate_note.py
@@ -191,7 +191,7 @@ def __init__(
         # rate params
         float_spread: DualTypes_ = NoInput(0),
         spread_compound_method: str_ = NoInput(0),
-        rate_fixings: LegFixings = NoInput(0),  # type: ignore[type-var]
+        rate_fixings: LegFixings = NoInput(0),
         fixing_method: str_ = NoInput(0),
         method_param: int_ = NoInput(0),
         fixing_frequency: Frequency | str_ = NoInput(0),
diff --git a/python/rateslib/instruments/bonds/index_fixed_rate_bond.py b/python/rateslib/instruments/bonds/index_fixed_rate_bond.py
index fd052ffd..bb27eff2 100644
--- a/python/rateslib/instruments/bonds/index_fixed_rate_bond.py
+++ b/python/rateslib/instruments/bonds/index_fixed_rate_bond.py
@@ -198,7 +198,7 @@ def __init__(
         index_base: DualTypes_ = NoInput(0),
         index_lag: int_ = NoInput(0),
         index_method: IndexMethod | str_ = NoInput(0),
-        index_fixings: LegFixings = NoInput(0),  # type: ignore[type-var]
+        index_fixings: LegFixings = NoInput(0),
         # rate parameters
         fixed_rate: DualTypes_ = NoInput(0),
         # meta parameters
diff --git a/python/rateslib/instruments/fra.py b/python/rateslib/instruments/fra.py
index 9004eda9..2df09761 100644
--- a/python/rateslib/instruments/fra.py
+++ b/python/rateslib/instruments/fra.py
@@ -309,7 +309,7 @@ def __init__(
         notional: DualTypes_ = NoInput(0),
         # rate parameters
         fixed_rate: DualTypes_ = NoInput(0),
-        leg2_rate_fixings: FixingsRates_ = NoInput(0),  # type: ignore[type-var]
+        leg2_rate_fixings: FixingsRates_ = NoInput(0),
         leg2_method_param: int_ = NoInput(0),
         leg2_fixing_frequency: Frequency | str_ = NoInput(0),
         leg2_fixing_series: FloatRateSeries | str_ = NoInput(0),
diff --git a/python/rateslib/instruments/iirs.py b/python/rateslib/instruments/iirs.py
index 6b507595..7a7e1b71 100644
--- a/python/rateslib/instruments/iirs.py
+++ b/python/rateslib/instruments/iirs.py
@@ -308,12 +308,12 @@ def __init__(
         index_base: DualTypes_ = NoInput(0),
         index_lag: int_ = NoInput(0),
         index_method: IndexMethod | str_ = NoInput(0),
-        index_fixings: LegFixings = NoInput(0),  # type: ignore[type-var]
+        index_fixings: LegFixings = NoInput(0),
         # rate params
         fixed_rate: DualTypes_ = NoInput(0),
         leg2_float_spread: DualTypes_ = NoInput(0),
         leg2_spread_compound_method: str_ = NoInput(0),
-        leg2_rate_fixings: FixingsRates_ = NoInput(0),  # type: ignore[type-var]
+        leg2_rate_fixings: FixingsRates_ = NoInput(0),
         leg2_fixing_method: str_ = NoInput(0),
         leg2_method_param: int_ = NoInput(0),
         # meta params
diff --git a/python/rateslib/instruments/irs.py b/python/rateslib/instruments/irs.py
index 5280280f..1414b914 100644
--- a/python/rateslib/instruments/irs.py
+++ b/python/rateslib/instruments/irs.py
@@ -294,7 +294,7 @@ def __init__(
         fixed_rate: DualTypes_ = NoInput(0),
         leg2_float_spread: DualTypes_ = NoInput(0),
         leg2_spread_compound_method: str_ = NoInput(0),
-        leg2_rate_fixings: FixingsRates_ = NoInput(0),  # type: ignore[type-var]
+        leg2_rate_fixings: FixingsRates_ = NoInput(0),
         leg2_fixing_method: str_ = NoInput(0),
         leg2_method_param: int_ = NoInput(0),
         leg2_fixing_frequency: Frequency | str_ = NoInput(0),
diff --git a/python/rateslib/instruments/ndf.py b/python/rateslib/instruments/ndf.py
index 828e0981..2a5279b6 100644
--- a/python/rateslib/instruments/ndf.py
+++ b/python/rateslib/instruments/ndf.py
@@ -223,7 +223,7 @@ def __init__(
         eom: bool_ = NoInput(0),
         # rate
         fx_rate: DualTypes_ = NoInput(0),
-        fx_fixings: PeriodFixings = NoInput(0),  # type: ignore[type-var]
+        fx_fixings: PeriodFixings = NoInput(0),
         leg2_fx_fixings: PeriodFixings = NoInput(0),
         reversed: bool = False,  # noqa: A002
         leg2_reversed: bool = False,
diff --git a/python/rateslib/instruments/sbs.py b/python/rateslib/instruments/sbs.py
index 15d65168..368c2dae 100644
--- a/python/rateslib/instruments/sbs.py
+++ b/python/rateslib/instruments/sbs.py
@@ -306,7 +306,7 @@ def __init__(
         # rate parameters
         float_spread: DualTypes_ = NoInput(0),
         spread_compound_method: str_ = NoInput(0),
-        rate_fixings: LegFixings = NoInput(0),  # type: ignore[type-var]
+        rate_fixings: LegFixings = NoInput(0),
         fixing_method: str_ = NoInput(0),
         method_param: int_ = NoInput(0),
         fixing_frequency: Frequency | str_ = NoInput(0),
diff --git a/python/rateslib/instruments/stir_future.py b/python/rateslib/instruments/stir_future.py
index 7b95e6a0..7a2d0579 100644
--- a/python/rateslib/instruments/stir_future.py
+++ b/python/rateslib/instruments/stir_future.py
@@ -314,7 +314,7 @@ def __init__(
         price: DualTypes_ = NoInput(0),
         leg2_float_spread: DualTypes_ = NoInput(0),
         leg2_spread_compound_method: str_ = NoInput(0),
-        leg2_rate_fixings: FixingsRates_ = NoInput(0),  # type: ignore[type-var]
+        leg2_rate_fixings: FixingsRates_ = NoInput(0),
         leg2_fixing_method: str_ = NoInput(0),
         leg2_method_param: int_ = NoInput(0),
         leg2_fixing_frequency: Frequency | str_ = NoInput(0),
diff --git a/python/rateslib/instruments/xcs.py b/python/rateslib/instruments/xcs.py
index aa431e18..9f65746b 100644
--- a/python/rateslib/instruments/xcs.py
+++ b/python/rateslib/instruments/xcs.py
@@ -454,12 +454,12 @@ def __init__(
         fixed_rate: DualTypes_ = NoInput(0),
         float_spread: DualTypes_ = NoInput(0),
         spread_compound_method: str_ = NoInput(0),
-        rate_fixings: FixingsRates_ = NoInput(0),  # type: ignore[type-var]
+        rate_fixings: FixingsRates_ = NoInput(0),
         fixing_method: str_ = NoInput(0),
         method_param: int_ = NoInput(0),
         fixing_frequency: Frequency | str_ = NoInput(0),
         fixing_series: FloatRateSeries | str_ = NoInput(0),
-        fx_fixings: LegFixings = NoInput(0),  # type: ignore[type-var]
+        fx_fixings: LegFixings = NoInput(0),
         leg2_fixed: bool = False,
         leg2_mtm: bool = False,
         leg2_fixed_rate: DualTypes_ = NoInput(0),
diff --git a/python/rateslib/instruments/zcis.py b/python/rateslib/instruments/zcis.py
index c0091c32..33fe73fc 100644
--- a/python/rateslib/instruments/zcis.py
+++ b/python/rateslib/instruments/zcis.py
@@ -238,7 +238,7 @@ def __init__(
         leg2_index_base: DualTypes_ = NoInput(0),
         leg2_index_lag: int_ = NoInput(0),
         leg2_index_method: IndexMethod | str_ = NoInput(0),
-        leg2_index_fixings: LegFixings = NoInput(0),  # type: ignore[type-var]
+        leg2_index_fixings: LegFixings = NoInput(0),
         # meta parameters
         curves: CurvesT_ = NoInput(0),
         spec: str_ = NoInput(0),
diff --git a/python/rateslib/instruments/zcs.py b/python/rateslib/instruments/zcs.py
index 678bb5bc..752946b0 100644
--- a/python/rateslib/instruments/zcs.py
+++ b/python/rateslib/instruments/zcs.py
@@ -311,7 +311,7 @@ def __init__(
         fixed_rate: DualTypes_ = NoInput(0),
         leg2_float_spread: DualTypes_ = NoInput(0),
         leg2_spread_compound_method: str_ = NoInput(0),
-        leg2_rate_fixings: FixingsRates_ = NoInput(0),  # type: ignore[type-var]
+        leg2_rate_fixings: FixingsRates_ = NoInput(0),
         leg2_fixing_method: str_ = NoInput(0),
         leg2_method_param: int_ = NoInput(0),
         leg2_fixing_frequency: Frequency | str_ = NoInput(0),
diff --git a/python/rateslib/legs/fixed.py b/python/rateslib/legs/fixed.py
index 3e699ee1..c1954f76 100644
--- a/python/rateslib/legs/fixed.py
+++ b/python/rateslib/legs/fixed.py
@@ -503,7 +503,7 @@ def __init__(
         currency: str_ = NoInput(0),
         # non-deliverable
         pair: str_ = NoInput(0),
-        fx_fixings: LegFixings = NoInput(0),  # type: ignore[type-var]
+        fx_fixings: LegFixings = NoInput(0),
         mtm: bool = False,
         # period
         convention: str_ = NoInput(0),
diff --git a/python/rateslib/legs/float.py b/python/rateslib/legs/float.py
index f8a252a2..f21fc979 100644
--- a/python/rateslib/legs/float.py
+++ b/python/rateslib/legs/float.py
@@ -250,7 +250,7 @@ def __init__(
         currency: str_ = NoInput(0),
         # non-deliverable
         pair: str_ = NoInput(0),
-        fx_fixings: LegFixings = NoInput(0),  # type: ignore[type-var]
+        fx_fixings: LegFixings = NoInput(0),
         mtm: bool = False,
         # period
         convention: str_ = NoInput(0),
diff --git a/python/rateslib/periods/parameters/rate.py b/python/rateslib/periods/parameters/rate.py
index 80ce26fb..ff09125d 100644
--- a/python/rateslib/periods/parameters/rate.py
+++ b/python/rateslib/periods/parameters/rate.py
@@ -47,7 +47,7 @@
 
 def _init_FloatRateParams(
     _float_spread: DualTypes_,
-    _rate_fixings: PeriodFixings,  # type: ignore[type-var]
+    _rate_fixings: PeriodFixings,
     _fixing_method: FloatFixingMethod | str_,
     _method_param: int_,
     _spread_compound_method: SpreadCompoundMethod | str_,
diff --git a/requirements.txt b/requirements.txt
index 8d10fd1e..466435cd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -18,7 +18,7 @@ nbsphinx>=0.9.5,<1.0
 pickleshare>=0.7.5,<1.0
 
 ruff>=0.11.0,<1.0  # for code linting
-mypy>=1.16.0,<1.18  # for type checking
+mypy>=1.16.0,<1.20  # for type checking
 pandas-stubs>=2.0,<3.0
 
 jupyterlab>=4.0,<5.0