diff --git a/http2/http2.go b/http2/http2.go
index bdaba1d..27cc893 100644
--- a/http2/http2.go
+++ b/http2/http2.go
@@ -19,7 +19,6 @@
 import (
 	"bufio"
 	"crypto/tls"
-	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -173,11 +172,6 @@
 	return fmt.Sprintf("UNKNOWN_SETTING_%d", uint16(s))
 }
 
-var (
-	errInvalidHeaderFieldName  = errors.New("http2: invalid header field name")
-	errInvalidHeaderFieldValue = errors.New("http2: invalid header field value")
-)
-
 // validWireHeaderFieldName reports whether v is a valid header field
 // name (key). See httpguts.ValidHeaderName for the base rules.
 //
diff --git a/http2/transport.go b/http2/transport.go
index d948e96..81778be 100644
--- a/http2/transport.go
+++ b/http2/transport.go
@@ -2198,8 +2198,6 @@
 	return nil
 }
 
-var errInvalidTrailers = errors.New("http2: invalid trailers")
-
 func (rl *clientConnReadLoop) endStream(cs *clientStream) {
 	// TODO: check that any declared content-length matches, like
 	// server.go's (*stream).endStream method.
@@ -2430,7 +2428,6 @@
 var (
 	errResponseHeaderListSize = errors.New("http2: response header list larger than advertised limit")
 	errRequestHeaderListSize  = errors.New("http2: request header list larger than peer's advertised limit")
-	errPseudoTrailers         = errors.New("http2: invalid pseudo header in trailers")
 )
 
 func (cc *ClientConn) logf(format string, args ...interface{}) {