diff --git a/src/library/attribute_manager.cpp b/src/library/attribute_manager.cpp
index aa54f39bec..91c2782f65 100644
--- a/src/library/attribute_manager.cpp
+++ b/src/library/attribute_manager.cpp
@@ -15,7 +15,6 @@ Author: Leonardo de Moura
 
 namespace lean {
 template class typed_attribute<indices_attribute_data>;
-template class typed_attribute<key_value_data>;
 
 static name_map<attribute_ptr> * g_system_attributes = nullptr;
 static user_attribute_ext * g_user_attribute_ext     = nullptr;
diff --git a/src/library/attribute_manager.h b/src/library/attribute_manager.h
index 55f9103867..bf86cab086 100644
--- a/src/library/attribute_manager.h
+++ b/src/library/attribute_manager.h
@@ -205,57 +205,9 @@ struct indices_attribute_data : public attr_data {
     }
 };
 
-struct key_value_data : public attr_data {
-    // generalize: name_map<std::string> m_pairs;
-    std::string m_symbol;
-    std::string m_library;
-
-    virtual unsigned hash() const override {
-        // unsigned h = 0;
-        // // This isn't right ..., well maybe? I don't really know.
-        // // Rust's Hash trait is super good at this.
-        // m_pairs.for_each([&] (name const & n, std::string const & value) {
-        //         h += n.hash();
-        //         // h += ::lean::hash_str(value, h);
-        // });
-        return 0;
-    }
-
-    void write(serializer & s) const {
-        s << m_symbol;
-        s << m_library;
-    }
-
-    void read(deserializer & d) {
-        std::string m_symbol, m_library;
-        d >> m_symbol;
-        d >> m_library;
-    }
-
-    void parse(abstract_parser & p) override {
-        std::cout << "in extern parser" << std::endl;
-        std::string n = p.parse_string_lit();
-        std::string l = p.parse_string_lit();
-        std::cout << "link symbol: " << n << std::endl;
-        std::cout << "library symbol: " << l << std::endl;
-        this->m_symbol = n;
-        this->m_library = l;
-    }
-
-    virtual void print(std::ostream & out) override {
-        out << "external";
-        // for (auto p : m_idxs) {
-        //    out << " " << p + 1;
-        // }
-    }
-};
-
 /** \brief Attribute that represents a list of indices. input and output are 1-indexed for convenience. */
 typedef typed_attribute<indices_attribute_data> indices_attribute;
 
-/** \brief Attribute that represents a list of indices. input and output are 1-indexed for convenience. */
-typedef typed_attribute<key_value_data> key_value_attribute;
-
 class user_attribute_ext {
 public:
     virtual ~user_attribute_ext() {}