diff --git a/include/boost/lambda2/lambda2.hpp b/include/boost/lambda2/lambda2.hpp
index 77eee9a..ce7a735 100644
--- a/include/boost/lambda2/lambda2.hpp
+++ b/include/boost/lambda2/lambda2.hpp
@@ -89,6 +89,8 @@ namespace lambda2_detail
 BOOST_LAMBDA2_BINARY_FN(<<, left_shift)
 BOOST_LAMBDA2_BINARY_FN(>>, right_shift)
 
+BOOST_LAMBDA2_PREFIX_FN(+, unary_plus)
+
 // operators
 
 template<class T> using remove_cvref_t = std::remove_cv_t<std::remove_reference_t<T>>;
@@ -148,6 +150,8 @@ BOOST_LAMBDA2_UNARY_LAMBDA(~, std::bit_not<>)
 BOOST_LAMBDA2_BINARY_LAMBDA(<<, lambda2_detail::left_shift)
 BOOST_LAMBDA2_BINARY_LAMBDA(>>, lambda2_detail::right_shift)
 
+BOOST_LAMBDA2_UNARY_LAMBDA(+, lambda2_detail::unary_plus)
+
 } // namespace lambda2
 } // namespace boost
 
diff --git a/test/lambda2_test.cpp b/test/lambda2_test.cpp
index b4e4e73..5e1d81e 100644
--- a/test/lambda2_test.cpp
+++ b/test/lambda2_test.cpp
@@ -63,5 +63,7 @@ int main()
     TEST_BINARY(<<)
     TEST_BINARY(>>)
 
+    TEST_UNARY(+)
+
     return boost::report_errors();
 }