diff --git a/daemon/lua/sandbox.lua b/daemon/lua/sandbox.lua
index a7ca501c08ad6f1453ef432ffbd8f3542193786a..53559156ea1007b30c511a4cec6c239551a02266 100644
--- a/daemon/lua/sandbox.lua
+++ b/daemon/lua/sandbox.lua
@@ -141,7 +141,7 @@ function table_print (tt, indent, done)
 			if type (value) == "table" and not done [value] then
 				done [value] = true
 				result = result .. string.format("[%s] => {\n", tostring (key))
-				table_print (value, indent + 4, done)
+				result = result .. table_print (value, indent + 4, done)
 				result = result .. string.rep (" ", indent)
 				result = result .. "}\n"
 			else