diff --git a/openff/interchange/common/_nonbonded.py b/openff/interchange/common/_nonbonded.py
index 44d9cab5..be2b5202 100644
--- a/openff/interchange/common/_nonbonded.py
+++ b/openff/interchange/common/_nonbonded.py
@@ -101,7 +101,7 @@ class ElectrostaticsCollection(_NonbondedCollection):
     nonperiodic_potential: Literal["Coulomb", "cutoff", "no-cutoff"] = Field("Coulomb")
     exception_potential: Literal["Coulomb"] = Field("Coulomb")
 
-    _charges: dict[Any, _ElementaryChargeQuantity] = PrivateAttr(default_factory=dict)
+    _charges: dict[Any, _ElementaryChargeQuantity] = PrivateAttr()
     _charges_cached: bool = PrivateAttr(default=False)
 
     @computed_field  # type: ignore[misc]
diff --git a/openff/interchange/foyer/_nonbonded.py b/openff/interchange/foyer/_nonbonded.py
index 75a7e2fb..73208aad 100644
--- a/openff/interchange/foyer/_nonbonded.py
+++ b/openff/interchange/foyer/_nonbonded.py
@@ -60,7 +60,7 @@ class FoyerElectrostaticsHandler(ElectrostaticsCollection):
     force_field_key: str = "atoms"
     cutoff: _DistanceQuantity = 9.0 * unit.angstrom
 
-    _charges: dict[TopologyKey, Quantity] = PrivateAttr(default_factory=dict)
+    _charges: dict[TopologyKey, Quantity] = PrivateAttr()
 
     def store_charges(
         self,
diff --git a/openff/interchange/smirnoff/_nonbonded.py b/openff/interchange/smirnoff/_nonbonded.py
index b9835140..6306bcd4 100644
--- a/openff/interchange/smirnoff/_nonbonded.py
+++ b/openff/interchange/smirnoff/_nonbonded.py
@@ -273,7 +273,7 @@ class SMIRNOFFElectrostaticsCollection(ElectrostaticsCollection, SMIRNOFFCollect
     )  # type: ignore[assignment]
     exception_potential: Literal["Coulomb"] = Field("Coulomb")
 
-    _charges: dict[Any, _ElementaryChargeQuantity] = PrivateAttr(default_factory=dict)
+    _charges: dict[Any, _ElementaryChargeQuantity] = PrivateAttr()
     _charges_cached: bool = PrivateAttr(default=False)
 
     @classmethod