diff --git a/AddressBook.cpp b/AddressBook.cpp
index 799b3f75..788c2fb6 100644
--- a/AddressBook.cpp
+++ b/AddressBook.cpp
@@ -440,7 +440,7 @@ namespace client
 				request << "GET " << u.path_ << " HTTP/1.1\r\nHost: " << u.host_
 				<< "\r\nAccept: */*\r\n" << "User-Agent: Wget/1.11.4\r\n" << "Connection: close\r\n";
 				if (m_Etag.length () > 0) // etag
-					request << i2p::util::http::ETAG << ": " << m_Etag << "\r\n";
+					request << i2p::util::http::IF_NONE_MATCH << ": \"" << m_Etag << "\"\r\n";
 				if (m_LastModified.length () > 0) // if-modfief-since
 					request << i2p::util::http::IF_MODIFIED_SINCE << ": " << m_LastModified << "\r\n";
 				request << "\r\n"; // end of header
diff --git a/util.h b/util.h
index 04af97ae..e07b746e 100644
--- a/util.h
+++ b/util.h
@@ -41,6 +41,7 @@ namespace util
 	namespace http
 	{
 		const char ETAG[] = "ETag";
+		const char IF_NONE_MATCH[] = "If-None-Match";
 		const char IF_MODIFIED_SINCE[] = "If-Modified-Since";
 		const char LAST_MODIFIED[] = "Last-Modified";
 		const char TRANSFER_ENCODING[] = "Transfer-Encoding";