diff --git a/compose/service/module.go b/compose/service/module.go
index 2adebee1b..afb653a72 100644
--- a/compose/service/module.go
+++ b/compose/service/module.go
@@ -589,10 +589,19 @@ func updateModuleFields(ctx context.Context, s store.Storer, new, old *types.Mod
 func moduleFieldDefaultPreparer(ctx context.Context, s store.Storer, m *types.Module, newFields types.ModuleFieldSet) (types.ModuleFieldSet, error) {
 	var err error
 
+	// prepare an auxillary module to perform isolated validations on
+	auxm := &types.Module{
+		Handle:      "aux_module",
+		NamespaceID: m.NamespaceID,
+		Fields:      types.ModuleFieldSet{nil},
+	}
+
 	for _, f := range newFields {
 		if f.DefaultValue == nil || len(f.DefaultValue) == 0 {
 			continue
 		}
+		auxm.Fields[0] = f
+
 		vv := f.DefaultValue
 		vv.SetUpdatedFlag(true)
 		// Module field default values should not have a field name, so let's temporarily add it
@@ -601,21 +610,21 @@ func moduleFieldDefaultPreparer(ctx context.Context, s store.Storer, m *types.Mo
 			return nil
 		})
 
-		if err = RecordValueSanitization(m, vv); err != nil {
+		if err = RecordValueSanitization(auxm, vv); err != nil {
 			return nil, err
 		}
 
-		vv = values.Sanitizer().Run(m, vv)
+		vv = values.Sanitizer().Run(auxm, vv)
 
 		r := &types.Record{
 			Values: vv,
 		}
-		rve := defaultValidator().Run(ctx, s, m, r)
+		rve := defaultValidator().Run(ctx, s, auxm, r)
 		if !rve.IsValid() {
 			return nil, rve
 		}
 
-		vv = values.Formatter().Run(m, vv)
+		vv = values.Formatter().Run(auxm, vv)
 
 		// Module field default values should not have a field name, so let's remove it
 		vv.Walk(func(rv *types.RecordValue) error {
diff --git a/tests/compose/module_test.go b/tests/compose/module_test.go
index 3afa0be57..8c3e56270 100644
--- a/tests/compose/module_test.go
+++ b/tests/compose/module_test.go
@@ -265,6 +265,39 @@ func TestModuleFieldsUpdate(t *testing.T) {
 	h.a.Equal(m.Fields[1].Kind, "DateTime")
 }
 
+func TestModuleFieldsUpdate_defaults(t *testing.T) {
+	h := newHelper(t)
+	h.clearModules()
+
+	h.allow(types.NamespaceRBACResource.AppendWildcard(), "read")
+	ns := h.makeNamespace("some-namespace")
+	m := h.makeModule(ns, "some-module", &types.ModuleField{ID: id.Next(), Kind: "String", Name: "existing", Required: true, DefaultValue: types.RecordValueSet{&types.RecordValue{Value: "test"}}})
+	h.allow(types.ModuleRBACResource.AppendWildcard(), "update")
+
+	f := m.Fields[0]
+	fjs := fmt.Sprintf(`{ "name": "%s", "fields": [{ "fieldID": "%d", "name": "existing_edited", "kind": "String", "isRequired": true, "defaultValue": [{ "value": "test" }] }, { "name": "new", "kind": "Bool", "defaultValue": [{ "value": "1" }] }] }`, m.Name, f.ID)
+	h.apiInit().
+		Post(fmt.Sprintf("/namespace/%d/module/%d", ns.ID, m.ID)).
+		JSON(fjs).
+		Expect(t).
+		Status(http.StatusOK).
+		Assert(helpers.AssertNoErrors).
+		End()
+
+	m = h.lookupModuleByID(m.ID)
+	h.a.NotNil(m)
+	h.a.NotNil(m.Fields)
+	h.a.Len(m.Fields, 2)
+
+	h.a.Equal(m.Fields[0].Kind, "String")
+	h.a.Len(m.Fields[0].DefaultValue, 1)
+	h.a.Equal("test", m.Fields[0].DefaultValue[0].Value)
+
+	h.a.Equal(m.Fields[1].Kind, "Bool")
+	h.a.Len(m.Fields[1].DefaultValue, 1)
+	h.a.Equal("1", m.Fields[1].DefaultValue[0].Value)
+}
+
 func TestModuleFieldsDefaultValue(t *testing.T) {
 	var ns *types.Namespace