diff --git a/whisper/mailserver/mailserver.go b/whisper/mailserver/mailserver.go
index d7af4baae3..d2c3f116a1 100644
--- a/whisper/mailserver/mailserver.go
+++ b/whisper/mailserver/mailserver.go
@@ -169,7 +169,7 @@ func (s *WMailServer) validateRequest(peerID []byte, request *whisper.Envelope)
 	f := whisper.Filter{KeySym: s.key}
 	decrypted := request.Open(&f)
 	if decrypted == nil {
-		log.Warn(fmt.Sprintf("Failed to decrypt p2p request"))
+		log.Warn("Failed to decrypt p2p request")
 		return false, 0, 0, nil
 	}
 
@@ -181,19 +181,19 @@ func (s *WMailServer) validateRequest(peerID []byte, request *whisper.Envelope)
 	// if you want to check the signature, you can do it here. e.g.:
 	// if !bytes.Equal(peerID, src) {
 	if src == nil {
-		log.Warn(fmt.Sprintf("Wrong signature of p2p request"))
+		log.Warn("Wrong signature of p2p request")
 		return false, 0, 0, nil
 	}
 
 	var bloom []byte
 	payloadSize := len(decrypted.Payload)
 	if payloadSize < 8 {
-		log.Warn(fmt.Sprintf("Undersized p2p request"))
+		log.Warn("Undersized p2p request")
 		return false, 0, 0, nil
 	} else if payloadSize == 8 {
 		bloom = whisper.MakeFullNodeBloom()
 	} else if payloadSize < 8+whisper.BloomFilterSize {
-		log.Warn(fmt.Sprintf("Undersized bloom filter in p2p request"))
+		log.Warn("Undersized bloom filter in p2p request")
 		return false, 0, 0, nil
 	} else {
 		bloom = decrypted.Payload[8 : 8+whisper.BloomFilterSize]