diff --git a/include/stdplus/zstring_view.hpp b/include/stdplus/zstring_view.hpp
index 0c18bfb..19697f7 100644
--- a/include/stdplus/zstring_view.hpp
+++ b/include/stdplus/zstring_view.hpp
@@ -309,7 +309,7 @@
     return os << static_cast<std::basic_string_view<CharT, Traits>>(v);
 }
 
-namespace zstring_view_literals
+inline namespace zstring_view_literals
 {
 template <detail::compile_zstring_view Str>
 constexpr auto operator"" _zsv() noexcept
diff --git a/test/zstring_view.cpp b/test/zstring_view.cpp
index 8b29bc9..0ef7fb7 100644
--- a/test/zstring_view.cpp
+++ b/test/zstring_view.cpp
@@ -14,7 +14,6 @@
 
 using std::literals::string_literals::operator""s;
 using std::literals::string_view_literals::operator""sv;
-using zstring_view_literals::operator""_zsv;
 
 TEST(ZstringView, IsString)
 {