diff --git a/hack/generator/pkg/astmodel/std_references.go b/hack/generator/pkg/astmodel/std_references.go
index 62dec04b6fa..8c5093dc9f8 100644
--- a/hack/generator/pkg/astmodel/std_references.go
+++ b/hack/generator/pkg/astmodel/std_references.go
@@ -14,6 +14,7 @@ var (
 	ErrorsReference  = MakeExternalPackageReference("errors")
 	FmtReference     = MakeExternalPackageReference("fmt")
 	JsonReference    = MakeExternalPackageReference("encoding/json")
+	OSReference      = MakeExternalPackageReference("os")
 	ReflectReference = MakeExternalPackageReference("reflect")
 	TestingReference = MakeExternalPackageReference("testing")
 
diff --git a/hack/generator/pkg/codegen/pipeline/json_serialization_test_cases.go b/hack/generator/pkg/codegen/pipeline/json_serialization_test_cases.go
index e495ea40c2b..432fd936015 100644
--- a/hack/generator/pkg/codegen/pipeline/json_serialization_test_cases.go
+++ b/hack/generator/pkg/codegen/pipeline/json_serialization_test_cases.go
@@ -48,22 +48,47 @@ func InjectJsonSerializationTests(idFactory astmodel.IdentifierFactory) Stage {
 }
 
 type objectSerializationTestCaseFactory struct {
-	injector  *astmodel.TestCaseInjector
-	idFactory astmodel.IdentifierFactory
+	injector     *astmodel.TestCaseInjector
+	idFactory    astmodel.IdentifierFactory
+	suppressions []string
 }
 
 func makeObjectSerializationTestCaseFactory(idFactory astmodel.IdentifierFactory) objectSerializationTestCaseFactory {
 	result := objectSerializationTestCaseFactory{
 		injector:  astmodel.NewTestCaseInjector(),
 		idFactory: idFactory,
+		suppressions: []string{
+			"DatabaseAccounts_SpecARM",
+			"DatabaseAccountCreateUpdatePropertiesARM",
+			"BackupPolicyARM",
+		},
 	}
 
 	return result
 }
 
+// NeedsTest returns true if we should generate a testcase for the specified definition
 func (s *objectSerializationTestCaseFactory) NeedsTest(def astmodel.TypeDefinition) bool {
 	_, ok := astmodel.AsPropertyContainer(def.Type())
-	return ok
+	if !ok {
+		// Can only generate tests for property containers
+		return false
+	}
+
+	// Check for types that we need to suppress - these are ARM types that don't currently round trip because they're
+	// OneOf implementations that are only used in one direction.
+	//
+	// See https://github.com/Azure/azure-service-operator/issues/1721 for more information
+	//
+	result := true
+	for _, s := range s.suppressions {
+		if def.Name().Name() == s {
+			result = false
+			break
+		}
+	}
+
+	return result
 }
 
 func (s *objectSerializationTestCaseFactory) AddTestTo(def astmodel.TypeDefinition) (astmodel.TypeDefinition, error) {
diff --git a/hack/generator/pkg/testcases/json_serialization_test_case.go b/hack/generator/pkg/testcases/json_serialization_test_case.go
index e1aa94ad072..c657d60c76b 100644
--- a/hack/generator/pkg/testcases/json_serialization_test_case.go
+++ b/hack/generator/pkg/testcases/json_serialization_test_case.go
@@ -120,7 +120,8 @@ func (o *JSONSerializationTestCase) RequiredImports() *astmodel.PackageImportSet
 	result := astmodel.NewPackageImportSet()
 
 	// Standard Go Packages
-	result.AddImportsOfReferences(astmodel.JsonReference, astmodel.ReflectReference, astmodel.TestingReference)
+	result.AddImportsOfReferences(
+		astmodel.JsonReference, astmodel.OSReference, astmodel.ReflectReference, astmodel.TestingReference)
 
 	// Cmp
 	result.AddImportsOfReferences(astmodel.CmpReference, astmodel.CmpOptsReference)
@@ -167,6 +168,7 @@ func (o *JSONSerializationTestCase) createTestRunner(codegenContext *astmodel.Co
 	)
 
 	gopterPackage := codegenContext.MustGetImportedPackageName(astmodel.GopterReference)
+	osPackage := codegenContext.MustGetImportedPackageName(astmodel.OSReference)
 	propPackage := codegenContext.MustGetImportedPackageName(astmodel.GopterPropReference)
 	testingPackage := codegenContext.MustGetImportedPackageName(astmodel.TestingReference)
 
@@ -208,8 +210,14 @@ func (o *JSONSerializationTestCase) createTestRunner(codegenContext *astmodel.Co
 		testName,
 		propForAll)
 
-	// properties.TestingRun(t)
-	runTests := astbuilder.InvokeQualifiedFunc(propertiesLocal, testingRunMethod, t)
+	// properties.TestingRun(t, gopter.NewFormatedReporter(true, 160, os.Stdout))
+	createReporter := astbuilder.CallQualifiedFunc(
+		gopterPackage,
+		"NewFormatedReporter",
+		dst.NewIdent("true"),
+		astbuilder.IntLiteral(240),
+		astbuilder.Selector(dst.NewIdent(osPackage), "Stdout"))
+	runTests := astbuilder.InvokeQualifiedFunc(propertiesLocal, testingRunMethod, t, createReporter)
 
 	// Define our function
 	fn := astbuilder.NewTestFuncDetails(
diff --git a/hack/generator/pkg/testcases/testdata/TestJSONSerializationTestCase_AsFunc/person_test.golden b/hack/generator/pkg/testcases/testdata/TestJSONSerializationTestCase_AsFunc/person_test.golden
index d4ad32239ba..d8c33a3b293 100644
--- a/hack/generator/pkg/testcases/testdata/TestJSONSerializationTestCase_AsFunc/person_test.golden
+++ b/hack/generator/pkg/testcases/testdata/TestJSONSerializationTestCase_AsFunc/person_test.golden
@@ -12,6 +12,7 @@ import (
 	"github.com/leanovate/gopter"
 	"github.com/leanovate/gopter/gen"
 	"github.com/leanovate/gopter/prop"
+	"os"
 	"reflect"
 	"testing"
 )
@@ -23,7 +24,7 @@ func Test_Person_Spec_WhenSerializedToJson_DeserializesAsEqual(t *testing.T) {
 	properties.Property(
 		"Round trip of Person_Spec via JSON returns original",
 		prop.ForAll(RunJSONSerializationTestForPersonSpec, PersonSpecGenerator()))
-	properties.TestingRun(t)
+	properties.TestingRun(t, gopter.NewFormatedReporter(true, 240, os.Stdout))
 }
 
 // RunJSONSerializationTestForPersonSpec runs a test to see if a specific instance of Person_Spec round trips to JSON and back losslessly