diff --git a/typedefs.h b/typedefs.h
index 109da5318..3a042804f 100644
--- a/typedefs.h
+++ b/typedefs.h
@@ -25,8 +25,8 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 */
 
-#ifndef TYPEDEFS_H_
-#define TYPEDEFS_H_
+#ifndef TYPEDEFS_H
+#define TYPEDEFS_H
 
 #include <limits>
 
@@ -45,6 +45,7 @@ typedef int EdgeWeight;
 
 constexpr NodeID SPECIAL_NODEID = std::numeric_limits<unsigned>::max();
 constexpr EdgeID SPECIAL_EDGEID = std::numeric_limits<unsigned>::max();
+constexpr unsigned INVALID_NAMEID = std::numeric_limits<unsigned>::max();
 constexpr EdgeWeight INVALID_EDGE_WEIGHT = std::numeric_limits<int>::max();
 
-#endif /* TYPEDEFS_H_ */
+#endif /* TYPEDEFS_H */