diff --git a/src/lua/header_filter.lua b/src/lua/header_filter.lua
index 295d395..d7c3d17 100644
--- a/src/lua/header_filter.lua
+++ b/src/lua/header_filter.lua
@@ -11,10 +11,11 @@ if ngx.header["Content-Type"] then
        content_type:find("text/xml") or
        content_type:find("application/javascript") or
        content_type:find("application/json") or
-       content_type:find("application/rss+xml") or
-       content_type:find("application/atom+xml") or
-       content_type:find("application/vnd.mpegurl") or
-       content_type:find("application/x-mpegurl") then
+       content_type:find("application/rss%+xml") or
+       content_type:find("application/atom%+xml") or
+       content_type:find("application/vnd%.mpegurl") or
+       content_type:find("application/x%-mpegurl") then
+        ngx.log(ngx.DEBUG, "Enabling rewrite due to content type " .. content_type)
         ngx.ctx.rewriting = true
         ngx.header["Content-Length"] = nil  -- We're rewriting the body so this has the wrong value if set
     end