why not

diff --git a/ElvUI_SLE/core/toolkit.lua b/ElvUI_SLE/core/toolkit.lua
index 3d96939..c1ecb03 100644
--- a/ElvUI_SLE/core/toolkit.lua
+++ b/ElvUI_SLE/core/toolkit.lua
@@ -169,6 +169,7 @@ end
 --Math
 T.floor = floor
 T.tonumber = tonumber
+T.tostring = tostring
 --Groups
 T.IsInGroup = IsInGroup
 T.IsInRaid = IsInRaid