diff --git a/common/types/opaque_type.cc b/common/types/opaque_type.cc
index 002319d1d..9c58e8289 100644
--- a/common/types/opaque_type.cc
+++ b/common/types/opaque_type.cc
@@ -98,7 +98,7 @@ absl::optional<OptionalType> OpaqueType::AsOptional() const {
   if (IsOptional()) {
     return OptionalType(absl::in_place, *this);
   }
-  return absl::nullopt;
+  return std::nullopt;
 }
 
 OptionalType OpaqueType::GetOptional() const {
diff --git a/common/types/struct_type.cc b/common/types/struct_type.cc
index a1be1f786..69f531a2f 100644
--- a/common/types/struct_type.cc
+++ b/common/types/struct_type.cc
@@ -61,7 +61,7 @@ absl::optional<MessageType> StructType::AsMessage() const {
   if (const auto* alt = absl::get_if<MessageType>(&variant_); alt != nullptr) {
     return *alt;
   }
-  return absl::nullopt;
+  return std::nullopt;
 }
 
 MessageType StructType::GetMessage() const {