diff --git a/financepy/products/rates/ibor_swap.py b/financepy/products/rates/ibor_swap.py
index e6acca2f4..2aa6c7c79 100644
--- a/financepy/products/rates/ibor_swap.py
+++ b/financepy/products/rates/ibor_swap.py
@@ -52,10 +52,11 @@ def __init__(
         float_spread: float = 0.0,
         float_freq_type: FrequencyTypes = FrequencyTypes.QUARTERLY,
         float_dc_type: DayCountTypes = DayCountTypes.THIRTY_E_360,
-        cal_type: CalendarTypes = CalendarTypes.WEEKEND,
-        bd_type: BusDayAdjustTypes = BusDayAdjustTypes.FOLLOWING,
-        dg_type: DateGenRuleTypes = DateGenRuleTypes.BACKWARD,
-    ):
+        cal_type: CalendarTypes = CalendarTypes.WEEKEND,
+        bd_type: BusDayAdjustTypes = BusDayAdjustTypes.FOLLOWING,
+        dg_type: DateGenRuleTypes = DateGenRuleTypes.BACKWARD,
+        end_of_month: bool = False,
+    ):
         """Create an interest rate swap contract giving the contract start
         date, its maturity, fixed cpn, fixed leg frequency, fixed leg day
         count convention and notional. The floating leg parameters have default
@@ -97,10 +98,11 @@ def __init__(
             notional,
             principal,
             payment_lag,
-            cal_type,
-            bd_type,
-            dg_type,
-        )
+            cal_type,
+            bd_type,
+            dg_type,
+            end_of_month,
+        )
 
         self.float_leg = SwapFloatLeg(
             effective_dt,
@@ -112,10 +114,11 @@ def __init__(
             notional,
             principal,
             payment_lag,
-            cal_type,
-            bd_type,
-            dg_type,
-        )
+            cal_type,
+            bd_type,
+            dg_type,
+            end_of_month,
+        )
 
     ###########################################################################
 
diff --git a/unit_tests/test_FinIborSwap.py b/unit_tests/test_FinIborSwap.py
new file mode 100644
index 000000000..43da6be74
--- /dev/null
+++ b/unit_tests/test_FinIborSwap.py
@@ -0,0 +1,94 @@
+from financepy.market.curves import InterpTypes
+from financepy.products.rates.ibor_single_curve import IborSingleCurve
+from financepy.products.rates.ibor_swap import IborSwap
+from financepy.utils import (
+    BusDayAdjustTypes,
+    Date,
+    DayCountTypes,
+    FrequencyTypes,
+    SwapTypes,
+)
+
+
+def test_ibor_swap_end_of_month_aligns_coupon_grid():
+    valuation_date = Date(31, 5, 2023)
+
+    swaps = []
+    for tenor in ["6M", "1Y"]:
+        swaps.append(
+            IborSwap(
+                effective_dt=valuation_date,
+                term_dt_or_tenor=tenor,
+                fixed_leg_type=SwapTypes.PAY,
+                fixed_cpn=0.01,
+                fixed_freq_type=FrequencyTypes.QUARTERLY,
+                fixed_dc_type=DayCountTypes.ACT_360,
+                float_dc_type=DayCountTypes.ACT_360,
+                bd_type=BusDayAdjustTypes.NONE,
+                end_of_month=True,
+            )
+        )
+
+    assert swaps[0].fixed_leg.payment_dts == [
+        Date(31, 8, 2023),
+        Date(30, 11, 2023),
+    ]
+    assert swaps[1].fixed_leg.payment_dts[:2] == swaps[0].fixed_leg.payment_dts
+
+    IborSingleCurve(
+        value_dt=valuation_date,
+        ibor_deposits=[],
+        ibor_fras=[],
+        ibor_swaps=swaps,
+        interp_type=InterpTypes.FLAT_FWD_RATES,
+    )
+
+
+def test_ibor_swap_end_of_month_handles_non_eom_effective_date():
+    swap = IborSwap(
+        effective_dt=Date(15, 5, 2023),
+        term_dt_or_tenor="1Y",
+        fixed_leg_type=SwapTypes.PAY,
+        fixed_cpn=0.01,
+        fixed_freq_type=FrequencyTypes.QUARTERLY,
+        fixed_dc_type=DayCountTypes.ACT_360,
+        float_dc_type=DayCountTypes.ACT_360,
+        bd_type=BusDayAdjustTypes.NONE,
+        end_of_month=True,
+    )
+
+    assert swap.fixed_leg.payment_dts == [
+        Date(31, 5, 2023),
+        Date(31, 8, 2023),
+        Date(30, 11, 2023),
+        Date(29, 2, 2024),
+        Date(15, 5, 2024),
+    ]
+
+
+def test_ibor_swap_end_of_month_applies_to_float_leg_schedule():
+    swap = IborSwap(
+        effective_dt=Date(31, 5, 2023),
+        term_dt_or_tenor="1Y",
+        fixed_leg_type=SwapTypes.PAY,
+        fixed_cpn=0.01,
+        fixed_freq_type=FrequencyTypes.ANNUAL,
+        fixed_dc_type=DayCountTypes.ACT_360,
+        float_freq_type=FrequencyTypes.QUARTERLY,
+        float_dc_type=DayCountTypes.ACT_360,
+        bd_type=BusDayAdjustTypes.NONE,
+        end_of_month=True,
+    )
+
+    assert swap.float_leg.payment_dts == [
+        Date(31, 8, 2023),
+        Date(30, 11, 2023),
+        Date(29, 2, 2024),
+        Date(31, 5, 2024),
+    ]
+    assert swap.float_leg.start_accrued_dts == [
+        Date(31, 5, 2023),
+        Date(31, 8, 2023),
+        Date(30, 11, 2023),
+        Date(29, 2, 2024),
+    ]