diff --git a/kong/cmd/utils/prefix_handler.lua b/kong/cmd/utils/prefix_handler.lua
index ea52071f1ff..d99fbc72b98 100644
--- a/kong/cmd/utils/prefix_handler.lua
+++ b/kong/cmd/utils/prefix_handler.lua
@@ -177,7 +177,7 @@ local function compile_conf(kong_config, conf_template)
   local post_template = pl_template.substitute(conf_template, compile_env)
   return string.gsub(post_template, "(${%b{}})", function(w)
     local name = w:sub(4, -3)
-    return compile_env[name:lower()]
+    return compile_env[name:lower()] or ""
   end)
 end