diff --git a/resources/[essential]/es_extended/locale.lua b/resources/[essential]/es_extended/locale.lua
index 5fd59603..c8b11067 100644
--- a/resources/[essential]/es_extended/locale.lua
+++ b/resources/[essential]/es_extended/locale.lua
@@ -5,5 +5,5 @@ function _(str, ...)	-- Translate string
 end
 
 function _U(str, ...) -- Translate string first char uppercase
-  return _(str, ...):gsub("^%l", string.upper)
+  return tostring(_(str, ...):gsub("^%l", string.upper))
 end