diff --git a/bittorrent/request_sanitizer.go b/bittorrent/request_sanitizer.go
deleted file mode 100644
index 1e6c48a..0000000
--- a/bittorrent/request_sanitizer.go
+++ /dev/null
@@ -1,61 +0,0 @@
-package bittorrent
-
-import (
-	"net"
-
-	log "github.com/sirupsen/logrus"
-)
-
-// ErrInvalidIP indicates an invalid IP for an Announce.
-var ErrInvalidIP = ClientError("invalid IP")
-
-// RequestSanitizer is used to replace unreasonable values in requests parsed
-// from a frontend into sane values.
-type RequestSanitizer struct {
-	MaxNumWant          uint32 `yaml:"max_numwant"`
-	DefaultNumWant      uint32 `yaml:"default_numwant"`
-	MaxScrapeInfoHashes uint32 `yaml:"max_scrape_infohashes"`
-}
-
-// SanitizeAnnounce enforces a max and default NumWant and coerces the peer's
-// IP address into the proper format.
-func (rs *RequestSanitizer) SanitizeAnnounce(r *AnnounceRequest) error {
-	if !r.NumWantProvided {
-		r.NumWant = rs.DefaultNumWant
-	} else if r.NumWant > rs.MaxNumWant {
-		r.NumWant = rs.MaxNumWant
-	}
-
-	if ip := r.Peer.IP.To4(); ip != nil {
-		r.Peer.IP.IP = ip
-		r.Peer.IP.AddressFamily = IPv4
-	} else if len(r.Peer.IP.IP) == net.IPv6len { // implies r.Peer.IP.To4() == nil
-		r.Peer.IP.AddressFamily = IPv6
-	} else {
-		return ErrInvalidIP
-	}
-
-	log.Debug("sanitized announce", rs, r)
-	return nil
-}
-
-// SanitizeScrape enforces a max number of infohashes for a single scrape
-// request.
-func (rs *RequestSanitizer) SanitizeScrape(r *ScrapeRequest) error {
-	if len(r.InfoHashes) > int(rs.MaxScrapeInfoHashes) {
-		r.InfoHashes = r.InfoHashes[:rs.MaxScrapeInfoHashes]
-	}
-
-	log.Debug("sanitized scrape", rs, r)
-	return nil
-}
-
-// LogFields renders the request sanitizer's configuration as a set of loggable
-// fields.
-func (rs *RequestSanitizer) LogFields() log.Fields {
-	return log.Fields{
-		"maxNumWant":          rs.MaxNumWant,
-		"defaultNumWant":      rs.DefaultNumWant,
-		"maxScrapeInfohashes": rs.MaxScrapeInfoHashes,
-	}
-}
diff --git a/bittorrent/sanitize.go b/bittorrent/sanitize.go
new file mode 100644
index 0000000..9cc7402
--- /dev/null
+++ b/bittorrent/sanitize.go
@@ -0,0 +1,48 @@
+package bittorrent
+
+import (
+	"net"
+
+	"github.com/chihaya/chihaya/pkg/log"
+)
+
+// ErrInvalidIP indicates an invalid IP for an Announce.
+var ErrInvalidIP = ClientError("invalid IP")
+
+// SanitizeAnnounce enforces a max and default NumWant and coerces the peer's
+// IP address into the proper format.
+func SanitizeAnnounce(r *AnnounceRequest, maxNumWant, defaultNumWant uint32) error {
+	if !r.NumWantProvided {
+		r.NumWant = defaultNumWant
+	} else if r.NumWant > maxNumWant {
+		r.NumWant = maxNumWant
+	}
+
+	if ip := r.Peer.IP.To4(); ip != nil {
+		r.Peer.IP.IP = ip
+		r.Peer.IP.AddressFamily = IPv4
+	} else if len(r.Peer.IP.IP) == net.IPv6len { // implies r.Peer.IP.To4() == nil
+		r.Peer.IP.AddressFamily = IPv6
+	} else {
+		return ErrInvalidIP
+	}
+
+	log.Debug("sanitized announce", r, log.Fields{
+		"maxNumWant":     maxNumWant,
+		"defaultNumWant": defaultNumWant,
+	})
+	return nil
+}
+
+// SanitizeScrape enforces a max number of infohashes for a single scrape
+// request.
+func SanitizeScrape(r *ScrapeRequest, maxScrapeInfoHashes uint32) error {
+	if len(r.InfoHashes) > int(maxScrapeInfoHashes) {
+		r.InfoHashes = r.InfoHashes[:maxScrapeInfoHashes]
+	}
+
+	log.Debug("sanitized scrape", r, log.Fields{
+		"maxScrapeInfoHashes": maxScrapeInfoHashes,
+	})
+	return nil
+}
diff --git a/frontend/http/frontend.go b/frontend/http/frontend.go
index dc10dab..1ed1323 100644
--- a/frontend/http/frontend.go
+++ b/frontend/http/frontend.go
@@ -21,9 +21,6 @@ func init() {
 	prometheus.MustRegister(promResponseDurationMilliseconds)
 }
 
-// ErrInvalidIP indicates an invalid IP.
-var ErrInvalidIP = bittorrent.ClientError("invalid IP")
-
 var promResponseDurationMilliseconds = prometheus.NewHistogramVec(
 	prometheus.HistogramOpts{
 		Name:    "chihaya_http_response_duration_milliseconds",
@@ -84,7 +81,7 @@ func (cfg Config) LogFields() log.Fields {
 		"realIPHeader":        cfg.RealIPHeader,
 		"maxNumWant":          cfg.MaxNumWant,
 		"defaultNumWant":      cfg.DefaultNumWant,
-		"maxScrapeInfohashes": cfg.MaxScrapeInfoHashes,
+		"maxScrapeInfoHashes": cfg.MaxScrapeInfoHashes,
 	}
 }
 
@@ -280,7 +277,7 @@ func (f *Frontend) scrapeRoute(w http.ResponseWriter, r *http.Request, _ httprou
 		req.AddressFamily = bittorrent.IPv6
 	} else {
 		log.Error("http: invalid IP: neither v4 nor v6", log.Fields{"RemoteAddr": r.RemoteAddr})
-		WriteError(w, ErrInvalidIP)
+		WriteError(w, bittorrent.ErrInvalidIP)
 		return
 	}
 	af = new(bittorrent.AddressFamily)
diff --git a/frontend/http/parser.go b/frontend/http/parser.go
index 29178bd..c463936 100644
--- a/frontend/http/parser.go
+++ b/frontend/http/parser.go
@@ -13,9 +13,11 @@ import (
 // If RealIPHeader is not empty string, the value of the first HTTP Header with
 // that name will be used.
 type ParseOptions struct {
-	AllowIPSpoofing             bool   `yaml:"allowIPSpoofing"`
-	RealIPHeader                string `yaml:"realIPHeader"`
-	bittorrent.RequestSanitizer `yaml:",inline"`
+	AllowIPSpoofing     bool   `yaml:"allow_ip_spoofing"`
+	RealIPHeader        string `yaml:"real_ip_header"`
+	MaxNumWant          uint32 `yaml:"max_numwant"`
+	DefaultNumWant      uint32 `yaml:"default_numwant"`
+	MaxScrapeInfoHashes uint32 `yaml:"max_scrape_infohashes"`
 }
 
 // ParseAnnounce parses an bittorrent.AnnounceRequest from an http.Request.
@@ -102,7 +104,7 @@ func ParseAnnounce(r *http.Request, opts ParseOptions) (*bittorrent.AnnounceRequ
 		return nil, bittorrent.ClientError("failed to parse peer IP address")
 	}
 
-	if err := opts.SanitizeAnnounce(request); err != nil {
+	if err := bittorrent.SanitizeAnnounce(request, opts.MaxNumWant, opts.DefaultNumWant); err != nil {
 		return nil, err
 	}
 
@@ -126,7 +128,7 @@ func ParseScrape(r *http.Request, opts ParseOptions) (*bittorrent.ScrapeRequest,
 		Params:     qp,
 	}
 
-	if err := opts.SanitizeScrape(request); err != nil {
+	if err := bittorrent.SanitizeScrape(request, opts.MaxScrapeInfoHashes); err != nil {
 		return nil, err
 	}
 
diff --git a/frontend/udp/frontend.go b/frontend/udp/frontend.go
index e50d182..54a3b23 100644
--- a/frontend/udp/frontend.go
+++ b/frontend/udp/frontend.go
@@ -26,9 +26,6 @@ func init() {
 	prometheus.MustRegister(promResponseDurationMilliseconds)
 }
 
-// ErrInvalidIP indicates an invalid IP.
-var ErrInvalidIP = bittorrent.ClientError("invalid IP")
-
 var promResponseDurationMilliseconds = prometheus.NewHistogramVec(
 	prometheus.HistogramOpts{
 		Name:    "chihaya_udp_response_duration_milliseconds",
@@ -84,7 +81,7 @@ func (cfg Config) LogFields() log.Fields {
 		"allowIPSpoofing":     cfg.AllowIPSpoofing,
 		"maxNumWant":          cfg.MaxNumWant,
 		"defaultNumWant":      cfg.DefaultNumWant,
-		"maxScrapeInfohashes": cfg.MaxScrapeInfoHashes,
+		"maxScrapeInfoHashes": cfg.MaxScrapeInfoHashes,
 	}
 }
 
@@ -317,7 +314,7 @@ func (t *Frontend) handleRequest(r Request, w ResponseWriter) (actionName string
 			req.AddressFamily = bittorrent.IPv6
 		} else {
 			log.Error("udp: invalid IP: neither v4 nor v6", log.Fields{"IP": r.IP})
-			WriteError(w, txID, ErrInvalidIP)
+			WriteError(w, txID, bittorrent.ErrInvalidIP)
 			return
 		}
 		af = new(bittorrent.AddressFamily)
diff --git a/frontend/udp/parser.go b/frontend/udp/parser.go
index e35e3b4..5a668f6 100644
--- a/frontend/udp/parser.go
+++ b/frontend/udp/parser.go
@@ -49,8 +49,10 @@ var (
 //
 // If AllowIPSpoofing is true, IPs provided via params will be used.
 type ParseOptions struct {
-	AllowIPSpoofing             bool `yaml:"allowIPSpoofing"`
-	bittorrent.RequestSanitizer `yaml:",inline"`
+	AllowIPSpoofing     bool   `yaml:"allow_ip_spoofing"`
+	MaxNumWant          uint32 `yaml:"max_numwant"`
+	DefaultNumWant      uint32 `yaml:"default_numwant"`
+	MaxScrapeInfoHashes uint32 `yaml:"max_scrape_infohashes"`
 }
 
 // ParseAnnounce parses an AnnounceRequest from a UDP request.
@@ -117,7 +119,7 @@ func ParseAnnounce(r Request, v6 bool, opts ParseOptions) (*bittorrent.AnnounceR
 		Params: params,
 	}
 
-	if err := opts.SanitizeAnnounce(request); err != nil {
+	if err := bittorrent.SanitizeAnnounce(request, opts.MaxNumWant, opts.DefaultNumWant); err != nil {
 		return nil, err
 	}
 
@@ -208,7 +210,7 @@ func ParseScrape(r Request, opts ParseOptions) (*bittorrent.ScrapeRequest, error
 
 	// Sanitize the request.
 	request := &bittorrent.ScrapeRequest{InfoHashes: infohashes}
-	if err := opts.SanitizeScrape(request); err != nil {
+	if err := bittorrent.SanitizeScrape(request, opts.MaxScrapeInfoHashes); err != nil {
 		return nil, err
 	}