diff --git a/instance.go b/instance.go
index 2c68879..e5cf113 100644
--- a/instance.go
+++ b/instance.go
@@ -23,6 +23,8 @@ type (
 	certificater interface{ Certificate(*pdk.PDK) }
 	rewriter     interface{ Rewrite(*pdk.PDK) }
 	accesser     interface{ Access(*pdk.PDK) }
+	headerFilter interface{ HeaderFilter(*pdk.PDK) }
+	bodyFilter   interface{ BodyFilter(*pdk.PDK) }
 	prereader    interface{ Preread(*pdk.PDK) }
 	logger       interface{ Log(*pdk.PDK) }
 )
@@ -33,6 +35,8 @@ func getHandlers(config interface{}) map[string]func(kong *pdk.PDK) {
 	if h, ok := config.(certificater); ok { handlers["certificate"]   = h.Certificate  }
 	if h, ok := config.(rewriter)    ; ok { handlers["rewrite"]       = h.Rewrite      }
 	if h, ok := config.(accesser)    ; ok { handlers["access"]        = h.Access       }
+	if h, ok := config.(headerFilter); ok { handlers["header_filter"] = h.HeaderFilter }
+	if h, ok := config.(bodyFilter)  ; ok { handlers["body_filter"]   = h.BodyFilter   }
 	if h, ok := config.(prereader)   ; ok { handlers["preread"]       = h.Preread      }
 	if h, ok := config.(logger)      ; ok { handlers["log"]           = h.Log          }