diff --git a/src/lua/body_filter.lua b/src/lua/body_filter.lua
index 3acd201..5cf2033 100644
--- a/src/lua/body_filter.lua
+++ b/src/lua/body_filter.lua
@@ -52,22 +52,24 @@ local function rewrite_body(body)
     return body
 end
 
-if ngx.ctx.rewriting then
-    local chunk = ngx.arg[1]
-    local eof = ngx.arg[2]
+if ngx.ctx.jasima_config then
+    if ngx.ctx.rewriting then
+        local chunk = ngx.arg[1]
+        local eof = ngx.arg[2]
 
-    ngx.ctx.buffered = (ngx.ctx.buffered or "") .. (chunk or "")
+        ngx.ctx.buffered = (ngx.ctx.buffered or "") .. (chunk or "")
 
-    if #ngx.ctx.buffered > 5 * 1024 * 1024 and not eof then
-        -- Don't just consume memory forever
-        ngx.arg[1] = rewrite_body(ngx.ctx.buffered)  -- We still do our best
-        ngx.ctx.rewriting = false
-        return
-    end
+        if #ngx.ctx.buffered > 5 * 1024 * 1024 and not eof then
+            -- Don't just consume memory forever
+            ngx.arg[1] = rewrite_body(ngx.ctx.buffered)  -- We still do our best
+            ngx.ctx.rewriting = false
+            return
+        end
 
-    if eof then
-        ngx.arg[1] = rewrite_body(ngx.ctx.buffered)
-    else
-        ngx.arg[1] = nil
+        if eof then
+            ngx.arg[1] = rewrite_body(ngx.ctx.buffered)
+        else
+            ngx.arg[1] = nil
+        end
     end
 end
diff --git a/src/lua/header_filter.lua b/src/lua/header_filter.lua
index d7c3d17..fba237b 100644
--- a/src/lua/header_filter.lua
+++ b/src/lua/header_filter.lua
@@ -1,29 +1,31 @@
 local utils = require "utils"
 
-if ngx.ctx.jasima_config.rewrite_disable then
-    return
-end
+if ngx.ctx.jasima_config then
+    if ngx.ctx.jasima_config.rewrite_disable then
+        return
+    end
 
-if ngx.header["Content-Type"] then
-    local content_type = ngx.header["Content-Type"]:lower()
-    if content_type:find("text/html") or
-       content_type:find("text/css") or
-       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
-        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
-end
-
-if ngx.header["Location"] then
-    if ngx.ctx.jasima_pool_map then
-        local location = ngx.header["Location"]
-        ngx.header["Location"] = location:gsub("//([%a%d%.-]+%.[%a%d-]+)/+", utils.get_mirror)
+    if ngx.header["Content-Type"] then
+        local content_type = ngx.header["Content-Type"]:lower()
+        if content_type:find("text/html") or
+           content_type:find("text/css") or
+           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
+            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
+    end
+
+    if ngx.header["Location"] then
+        if ngx.ctx.jasima_pool_map then
+            local location = ngx.header["Location"]
+            ngx.header["Location"] = location:gsub("//([%a%d%.-]+%.[%a%d-]+)/+", utils.get_mirror)
+        end
     end
 end