diff --git a/include/kth/domain/chain/input_basis.hpp b/include/kth/domain/chain/input_basis.hpp
index eb90d3b76..439627c3a 100644
--- a/include/kth/domain/chain/input_basis.hpp
+++ b/include/kth/domain/chain/input_basis.hpp
@@ -53,8 +53,11 @@ class KD_API input_basis {
     // Operators.
     //-------------------------------------------------------------------------
 
-    bool operator==(input_basis const& x) const;
-    bool operator!=(input_basis const& x) const;
+    friend
+    bool operator==(input_basis const&, input_basis const&) = default;
+
+    friend
+    bool operator!=(input_basis const&, input_basis const&) = default;
 
     // Deserialization.
     //-------------------------------------------------------------------------
diff --git a/include/kth/domain/chain/output.hpp b/include/kth/domain/chain/output.hpp
index e3136452a..32e7fb9cc 100644
--- a/include/kth/domain/chain/output.hpp
+++ b/include/kth/domain/chain/output.hpp
@@ -60,11 +60,6 @@ class KD_API output : public output_basis {
     output& operator=(output const& x);
     output& operator=(output&& x) noexcept;
 
-    // Operators.
-    //-------------------------------------------------------------------------
-    // bool operator==(output const& x) const;
-    // bool operator!=(output const& x) const;
-
     // Deserialization.
     //-------------------------------------------------------------------------
 
diff --git a/include/kth/domain/chain/output_basis.hpp b/include/kth/domain/chain/output_basis.hpp
index 44b1332f1..cb06fd90c 100644
--- a/include/kth/domain/chain/output_basis.hpp
+++ b/include/kth/domain/chain/output_basis.hpp
@@ -49,10 +49,11 @@ struct KD_API output_basis {
 
     // Operators.
     //-------------------------------------------------------------------------
-    // bool operator==(output_basis const& x) const;
-    // bool operator!=(output_basis const& x) const;
     friend
-    auto operator<=>(output_basis const&, output_basis const&) = default;
+    bool operator==(output_basis const&, output_basis const&) = default;
+
+    friend
+    bool operator!=(output_basis const&, output_basis const&) = default;
 
     // Deserialization.
     //-------------------------------------------------------------------------
diff --git a/include/kth/domain/chain/token_data.hpp b/include/kth/domain/chain/token_data.hpp
index 474821a9c..982244315 100644
--- a/include/kth/domain/chain/token_data.hpp
+++ b/include/kth/domain/chain/token_data.hpp
@@ -105,16 +105,23 @@ enum class capability_t : uint8_t {
 struct fungible {
     amount_t amount;
 
+
+    friend constexpr
+    bool operator==(fungible const&, fungible const&) = default;
+
     friend constexpr
-    auto operator<=>(fungible const&, fungible const&) = default;
+    bool operator!=(fungible const&, fungible const&) = default;
 };
 
 struct non_fungible {
     capability_t capability;
     commitment_t commitment;
 
-    friend
-    auto operator<=>(non_fungible const&, non_fungible const&) = default;
+    friend constexpr
+    bool operator==(non_fungible const&, non_fungible const&) = default;
+
+    friend constexpr
+    bool operator!=(non_fungible const&, non_fungible const&) = default;
 };
 
 using both_kinds = std::pair<fungible, non_fungible>;
@@ -124,7 +131,10 @@ struct token_data_t {
     std::variant<fungible, non_fungible, both_kinds> data;
 
     friend constexpr
-    auto operator<=>(token_data_t const&, token_data_t const&) = default;
+    bool operator==(token_data_t const&, token_data_t const&) = default;
+
+    friend constexpr
+    bool operator!=(token_data_t const&, token_data_t const&) = default;
 };
 
 using token_data_opt = std::optional<token_data_t>;
diff --git a/src/chain/input_basis.cpp b/src/chain/input_basis.cpp
index d2f39d3f4..f9f91d1ca 100644
--- a/src/chain/input_basis.cpp
+++ b/src/chain/input_basis.cpp
@@ -53,24 +53,6 @@ input_basis::input_basis(output_point&& previous_output, chain::script&& script,
 {}
 #endif
 
-
-// Operators.
-//-----------------------------------------------------------------------------
-
-bool input_basis::operator==(input_basis const& x) const {
-    return (sequence_ == x.sequence_)
-        && (previous_output_ == x.previous_output_)
-        && (script_ == x.script_)
-#if defined(KTH_SEGWIT_ENABLED)
-        && (witness_ == x.witness_)
-#endif
-        ;
-}
-
-bool input_basis::operator!=(input_basis const& x) const {
-    return !(*this == x);
-}
-
 void input_basis::reset() {
     previous_output_.reset();
     script_.reset();