diff --git a/src/misc_utilities/classifychars.cpp b/src/misc_utilities/classifychars.cpp
index e28fc78..3e9dd9c 100644
--- a/src/misc_utilities/classifychars.cpp
+++ b/src/misc_utilities/classifychars.cpp
@@ -44,6 +44,9 @@ const int RIGHT_ARROW_KEY = 3;
 const int DOWN_ARROW_KEY = 1;
 const int UP_ARROW_KEY= 0;
 
+const int ENTER_KEY_ONE = 13;
+const int ENTER_KEY_TWO = 10;
+
 #elif WIN32
 const int LEFT_ARROW_KEY = 2424832;
 const int RIGHT_ARROW_KEY = 2555904;