diff --git a/aten/src/ATen/core/op_registration/kernel_function_legacy_test.cpp b/aten/src/ATen/core/op_registration/kernel_function_legacy_test.cpp
index 687d5b59cda34..fd996e091aad8 100644
--- a/aten/src/ATen/core/op_registration/kernel_function_legacy_test.cpp
+++ b/aten/src/ATen/core/op_registration/kernel_function_legacy_test.cpp
@@ -803,9 +803,9 @@ TEST(OperatorRegistrationTest_LegacyFunctionBasedKernel, givenFallbackKernelWith
   EXPECT_EQ(4, outputs[0].toInt());
 }
 
-c10::optional<Tensor> called_arg2;
-c10::optional<int64_t> called_arg3;
-c10::optional<std::string> called_arg4;
+c10::optional<Tensor> called_arg2 = c10::nullopt;
+c10::optional<int64_t> called_arg3 = c10::nullopt;
+c10::optional<std::string> called_arg4 = c10::nullopt;
 
 void kernelWithOptInputWithoutOutput(Tensor arg1, const c10::optional<Tensor>& arg2, c10::optional<int64_t> arg3, c10::optional<std::string> arg4) {
   called = true;
diff --git a/aten/src/ATen/core/op_registration/kernel_function_test.cpp b/aten/src/ATen/core/op_registration/kernel_function_test.cpp
index 6f8f1fe090e6a..4a216a45caf5c 100644
--- a/aten/src/ATen/core/op_registration/kernel_function_test.cpp
+++ b/aten/src/ATen/core/op_registration/kernel_function_test.cpp
@@ -526,9 +526,9 @@ TEST(OperatorRegistrationTest_FunctionBasedKernel, givenFallbackKernelWithoutTen
   EXPECT_EQ(4, outputs[0].toInt());
 }
 
-c10::optional<Tensor> called_arg2;
-c10::optional<int64_t> called_arg3;
-c10::optional<std::string> called_arg4;
+c10::optional<Tensor> called_arg2 = c10::nullopt;
+c10::optional<int64_t> called_arg3 = c10::nullopt;
+c10::optional<std::string> called_arg4 = c10::nullopt;
 
 void kernelWithOptInputWithoutOutput(Tensor arg1, const c10::optional<Tensor>& arg2, c10::optional<int64_t> arg3, c10::optional<std::string> arg4) {
   called = true;
diff --git a/aten/src/ATen/core/op_registration/kernel_functor_test.cpp b/aten/src/ATen/core/op_registration/kernel_functor_test.cpp
index 66631fa4374c6..ce7e5d4eea4e4 100644
--- a/aten/src/ATen/core/op_registration/kernel_functor_test.cpp
+++ b/aten/src/ATen/core/op_registration/kernel_functor_test.cpp
@@ -675,9 +675,9 @@ TEST(OperatorRegistrationTest_FunctorBasedKernel, givenFallbackKernelWithoutTens
   EXPECT_EQ(4, outputs[0].toInt());
 }
 
-c10::optional<Tensor> called_arg2;
-c10::optional<int64_t> called_arg3;
-c10::optional<std::string> called_arg4;
+c10::optional<Tensor> called_arg2 = c10::nullopt;
+c10::optional<int64_t> called_arg3 = c10::nullopt;
+c10::optional<std::string> called_arg4 = c10::nullopt;
 
 struct KernelWithOptInputWithoutOutput final : OperatorKernel {
   void operator()(Tensor arg1, const c10::optional<Tensor>& arg2, c10::optional<int64_t> arg3, c10::optional<std::string> arg4) {
diff --git a/aten/src/ATen/core/op_registration/kernel_lambda_legacy_test.cpp b/aten/src/ATen/core/op_registration/kernel_lambda_legacy_test.cpp
index 73e0c1ac51719..d0dc2c4fd814e 100644
--- a/aten/src/ATen/core/op_registration/kernel_lambda_legacy_test.cpp
+++ b/aten/src/ATen/core/op_registration/kernel_lambda_legacy_test.cpp
@@ -729,9 +729,9 @@ TEST(OperatorRegistrationTest_LegacyLambdaBasedKernel, givenFallbackKernelWithou
 
 TEST(OperatorRegistrationTest_LegacyLambdaBasedKernel, givenKernelWithOptionalInputs_withoutOutput_whenRegistered_thenCanBeCalled) {
   bool called;
-  c10::optional<Tensor> called_arg2;
-  c10::optional<int64_t> called_arg3;
-  c10::optional<std::string> called_arg4;
+  c10::optional<Tensor> called_arg2 = c10::nullopt;
+  c10::optional<int64_t> called_arg3 = c10::nullopt;
+  c10::optional<std::string> called_arg4 = c10::nullopt;
 
   auto registrar = RegisterOperators().op(
     "_test::opt_input(Tensor arg1, Tensor? arg2, int? arg3, str? arg4) -> ()",
@@ -768,9 +768,9 @@ TEST(OperatorRegistrationTest_LegacyLambdaBasedKernel, givenKernelWithOptionalIn
 
 TEST(OperatorRegistrationTest_LegacyLambdaBasedKernel, givenKernelWithOptionalInputs_withOutput_whenRegistered_thenCanBeCalled) {
   bool called;
-  c10::optional<Tensor> called_arg2;
-  c10::optional<int64_t> called_arg3;
-  c10::optional<std::string> called_arg4;
+  c10::optional<Tensor> called_arg2 = c10::nullopt;
+  c10::optional<int64_t> called_arg3 = c10::nullopt;
+  c10::optional<std::string> called_arg4 = c10::nullopt;
 
   auto registrar = RegisterOperators().op(
     "_test::opt_input(Tensor arg1, Tensor? arg2, int? arg3, str? arg4) -> Tensor?",
@@ -810,9 +810,9 @@ TEST(OperatorRegistrationTest_LegacyLambdaBasedKernel, givenKernelWithOptionalIn
 
 TEST(OperatorRegistrationTest_LegacyLambdaBasedKernel, givenKernelWithOptionalInputs_withMultipleOutputs_whenRegistered_thenCanBeCalled) {
   bool called;
-  c10::optional<Tensor> called_arg2;
-  c10::optional<int64_t> called_arg3;
-  c10::optional<std::string> called_arg4;
+  c10::optional<Tensor> called_arg2 = c10::nullopt;
+  c10::optional<int64_t> called_arg3 = c10::nullopt;
+  c10::optional<std::string> called_arg4 = c10::nullopt;
 
   auto registrar = RegisterOperators().op(
     "_test::opt_input(Tensor arg1, Tensor? arg2, int? arg3, str? arg4) -> (Tensor?, int?, str?)",
diff --git a/aten/src/ATen/core/op_registration/kernel_lambda_test.cpp b/aten/src/ATen/core/op_registration/kernel_lambda_test.cpp
index 49202b077e326..f6e4c06867cd8 100644
--- a/aten/src/ATen/core/op_registration/kernel_lambda_test.cpp
+++ b/aten/src/ATen/core/op_registration/kernel_lambda_test.cpp
@@ -461,9 +461,9 @@ TEST(OperatorRegistrationTest_LambdaBasedKernel, givenFallbackKernelWithoutTenso
   EXPECT_EQ(4, outputs[0].toInt());
 }
 
-c10::optional<Tensor> called_arg2;
-c10::optional<int64_t> called_arg3;
-c10::optional<std::string> called_arg4;
+c10::optional<Tensor> called_arg2 = c10::nullopt;
+c10::optional<int64_t> called_arg3 = c10::nullopt;
+c10::optional<std::string> called_arg4 = c10::nullopt;
 
 TEST(OperatorRegistrationTest_LambdaBasedKernel, givenKernelWithOptionalInputs_withoutOutput_whenRegistered_thenCanBeCalled) {
   auto registrar = RegisterOperators().op(
diff --git a/aten/src/ATen/core/op_registration/op_registration.h b/aten/src/ATen/core/op_registration/op_registration.h
index daa7e7552a818..605317c8a5c41 100644
--- a/aten/src/ATen/core/op_registration/op_registration.h
+++ b/aten/src/ATen/core/op_registration/op_registration.h
@@ -425,7 +425,12 @@ class CAFFE2_API RegisterOperators final {
       );
     }
 
-    Options() = default;
+    Options()
+    : schemaOrName_(c10::nullopt)
+    , legacyATenSchema_(c10::nullopt)
+    , kernels()
+    , aliasAnalysisKind_(c10::nullopt)
+    {}
 
     // KernelRegistrationConfig accumulates all information from the config
     // parameters passed to a RegisterOperators::op() call into one object.
diff --git a/aten/src/ATen/core/op_registration/op_registration_test.cpp b/aten/src/ATen/core/op_registration/op_registration_test.cpp
index 4bfc120a1092f..2c00c3f5aef22 100644
--- a/aten/src/ATen/core/op_registration/op_registration_test.cpp
+++ b/aten/src/ATen/core/op_registration/op_registration_test.cpp
@@ -818,28 +818,28 @@ TEST(OperatorRegistrationTest, testAvailableArgTypes) {
 
   // optional types (with has_value() == false)
   testArgTypes<c10::optional<double>>::test(
-    c10::optional<double>(), [] (const c10::optional<double>& v) {EXPECT_FALSE(v.has_value());},
-    c10::optional<double>(), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
+    c10::optional<double>(c10::nullopt), [] (const c10::optional<double>& v) {EXPECT_FALSE(v.has_value());},
+    c10::optional<double>(c10::nullopt), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
     "(float? a) -> float?");
   testArgTypes<c10::optional<int64_t>>::test(
-    c10::optional<int64_t>(), [] (const c10::optional<int64_t>& v) {EXPECT_FALSE(v.has_value());},
-    c10::optional<int64_t>(), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
+    c10::optional<int64_t>(c10::nullopt), [] (const c10::optional<int64_t>& v) {EXPECT_FALSE(v.has_value());},
+    c10::optional<int64_t>(c10::nullopt), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
     "(int? a) -> int?");
   testArgTypes<c10::optional<bool>>::test(
-    c10::optional<bool>(), [] (const c10::optional<bool>& v) {EXPECT_FALSE(v.has_value());},
-    c10::optional<bool>(), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
+    c10::optional<bool>(c10::nullopt), [] (const c10::optional<bool>& v) {EXPECT_FALSE(v.has_value());},
+    c10::optional<bool>(c10::nullopt), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
     "(bool? a) -> bool?");
   testArgTypes<c10::optional<bool>>::test(
-    c10::optional<bool>(), [] (const c10::optional<bool>& v) {EXPECT_FALSE(v.has_value());},
-    c10::optional<bool>(), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
+    c10::optional<bool>(c10::nullopt), [] (const c10::optional<bool>& v) {EXPECT_FALSE(v.has_value());},
+    c10::optional<bool>(c10::nullopt), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
     "(bool? a) -> bool?");
   testArgTypes<c10::optional<std::string>>::test(
-    c10::optional<std::string>(), [] (const c10::optional<std::string>& v) {EXPECT_FALSE(v.has_value());},
-    c10::optional<std::string>(), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
+    c10::optional<std::string>(c10::nullopt), [] (const c10::optional<std::string>& v) {EXPECT_FALSE(v.has_value());},
+    c10::optional<std::string>(c10::nullopt), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
     "(str? a) -> str?");
   testArgTypes<c10::optional<Tensor>>::test(
-    c10::optional<Tensor>(), [] (const c10::optional<Tensor>& v) {EXPECT_FALSE(v.has_value());},
-    c10::optional<Tensor>(), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
+    c10::optional<Tensor>(c10::nullopt), [] (const c10::optional<Tensor>& v) {EXPECT_FALSE(v.has_value());},
+    c10::optional<Tensor>(c10::nullopt), [] (const IValue& v) {EXPECT_TRUE(v.isNone());},
     "(Tensor? a) -> Tensor?");