diff --git a/prometheus/http.go b/prometheus/http.go
index 9f0875b..0fa339a 100644
--- a/prometheus/http.go
+++ b/prometheus/http.go
@@ -34,7 +34,6 @@ import (
 
 const (
 	contentTypeHeader     = "Content-Type"
-	contentLengthHeader   = "Content-Length"
 	contentEncodingHeader = "Content-Encoding"
 	acceptEncodingHeader  = "Accept-Encoding"
 )
diff --git a/prometheus/promhttp/delegator.go b/prometheus/promhttp/delegator.go
index 67b56d3..5de5bbc 100644
--- a/prometheus/promhttp/delegator.go
+++ b/prometheus/promhttp/delegator.go
@@ -38,7 +38,6 @@ type delegator interface {
 type responseWriterDelegator struct {
 	http.ResponseWriter
 
-	handler, method    string
 	status             int
 	written            int64
 	wroteHeader        bool
diff --git a/prometheus/promhttp/http.go b/prometheus/promhttp/http.go
index 668eb6b..b137c88 100644
--- a/prometheus/promhttp/http.go
+++ b/prometheus/promhttp/http.go
@@ -47,7 +47,6 @@ import (
 
 const (
 	contentTypeHeader     = "Content-Type"
-	contentLengthHeader   = "Content-Length"
 	contentEncodingHeader = "Content-Encoding"
 	acceptEncodingHeader  = "Accept-Encoding"
 )