diff --git a/include/sol/types.hpp b/include/sol/types.hpp
index ac028bb9..667d7b8b 100644
--- a/include/sol/types.hpp
+++ b/include/sol/types.hpp
@@ -106,7 +106,7 @@ namespace sol {
 	}
 #if !defined(SOL_NO_NIL) || (SOL_NO_NIL == 0)
 	using nil_t = lua_nil_t;
-	constexpr nil_t& nil = lua_nil;
+	constexpr const nil_t& nil = lua_nil;
 #endif
 
 	namespace detail {
diff --git a/single/include/sol/forward.hpp b/single/include/sol/forward.hpp
index dea05b8e..2c0f93d5 100644
--- a/single/include/sol/forward.hpp
+++ b/single/include/sol/forward.hpp
@@ -20,8 +20,8 @@
 // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 // This file was generated with a script.
-// Generated 2019-05-26 17:32:11.611420 UTC
-// This header was generated with sol v3.0.2 (revision 4fd5d34)
+// Generated 2019-05-26 17:50:22.004134 UTC
+// This header was generated with sol v3.0.2 (revision a49fbc2)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_FORWARD_HPP
diff --git a/single/include/sol/sol.hpp b/single/include/sol/sol.hpp
index d33b2a71..e56f714b 100644
--- a/single/include/sol/sol.hpp
+++ b/single/include/sol/sol.hpp
@@ -20,8 +20,8 @@
 // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 // This file was generated with a script.
-// Generated 2019-05-26 17:32:11.338294 UTC
-// This header was generated with sol v3.0.2 (revision 4fd5d34)
+// Generated 2019-05-26 17:50:20.845211 UTC
+// This header was generated with sol v3.0.2 (revision a49fbc2)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_HPP
@@ -6297,7 +6297,7 @@ namespace sol {
 	}
 #if !defined(SOL_NO_NIL) || (SOL_NO_NIL == 0)
 	using nil_t = lua_nil_t;
-	constexpr nil_t& nil = lua_nil;
+	constexpr const nil_t& nil = lua_nil;
 #endif
 
 	namespace detail {