diff --git a/src/qrules/conservation_rules.py b/src/qrules/conservation_rules.py
index bb1cc356..b264f265 100644
--- a/src/qrules/conservation_rules.py
+++ b/src/qrules/conservation_rules.py
@@ -691,8 +691,8 @@ def spin_conservation(
 
 
 def spin_magnitude_conservation(
-    ingoing_spins: List[SpinEdgeInput],
-    outgoing_spins: List[SpinEdgeInput],
+    ingoing_spin_magnitudes: List[EdgeQN.spin_magnitude],
+    outgoing_spin_magnitudes: List[EdgeQN.spin_magnitude],
     interaction_qns: SpinMagnitudeNodeInput,
 ) -> bool:
     r"""Check for spin conservation.
@@ -710,20 +710,20 @@ def spin_magnitude_conservation(
     # L and S can only be used if one side is a single state
     # and the other side contains of two states (isobar)
     # So do a full check if this is the case
-    if (len(ingoing_spins) == 1 and len(outgoing_spins) == 2) or (
-        len(ingoing_spins) == 2 and len(outgoing_spins) == 1
+    if (len(ingoing_spin_magnitudes) == 1 and len(outgoing_spin_magnitudes) == 2) or (
+        len(ingoing_spin_magnitudes) == 2 and len(outgoing_spin_magnitudes) == 1
     ):
         return _check_magnitude(
-            [x.spin_magnitude for x in ingoing_spins],
-            [x.spin_magnitude for x in outgoing_spins],
+            [float(x) for x in ingoing_spin_magnitudes],
+            [float(x) for x in outgoing_spin_magnitudes],
             interaction_qns,
         )
 
     # otherwise don't use S and L and just check magnitude
     # are integral or non integral on both sides
     return (
-        sum(float(x.spin_magnitude) for x in ingoing_spins).is_integer()  # type: ignore[union-attr]
-        == sum(float(x.spin_magnitude) for x in outgoing_spins).is_integer()  # type: ignore[union-attr]
+        sum(float(x) for x in ingoing_spin_magnitudes).is_integer()  # type: ignore[union-attr]
+        == sum(float(x) for x in outgoing_spin_magnitudes).is_integer()  # type: ignore[union-attr]
     )
 
 
diff --git a/tests/unit/conservation_rules/test_spin.py b/tests/unit/conservation_rules/test_spin.py
index 3f370d3d..358ac1ad 100644
--- a/tests/unit/conservation_rules/test_spin.py
+++ b/tests/unit/conservation_rules/test_spin.py
@@ -11,8 +11,13 @@
     spin_magnitude_conservation,
 )
 from qrules.particle import Spin
+from qrules.quantum_numbers import EdgeQuantumNumbers
 
-_SpinRuleInputType = Tuple[List[SpinEdgeInput], List[SpinEdgeInput], SpinNodeInput]
+_SpinRuleInputType = Tuple[
+    List[EdgeQuantumNumbers.spin_magnitude],
+    List[EdgeQuantumNumbers.spin_magnitude],
+    SpinNodeInput,
+]
 
 
 def __create_two_body_decay_spin_data(