diff --git a/quic/core/quic_framer.cc b/quic/core/quic_framer.cc
index 5b061d7..6a6046c 100644
--- a/quic/core/quic_framer.cc
+++ b/quic/core/quic_framer.cc
@@ -1392,17 +1392,46 @@
     QuicConnectionId client_connection_id,
     bool ietf_quic,
     const ParsedQuicVersionVector& versions) {
+  ParsedQuicVersionVector wire_versions = versions;
+  if (!GetQuicReloadableFlag(quic_version_negotiation_grease)) {
+    if (wire_versions.empty()) {
+      wire_versions = {QuicVersionReservedForNegotiation()};
+    }
+  } else {
+    // Add a version reserved for negotiation as suggested by the
+    // "Using Reserved Versions" section of draft-ietf-quic-transport.
+    QUIC_RELOADABLE_FLAG_COUNT_N(quic_version_negotiation_grease, 1, 2);
+    if (wire_versions.empty()) {
+      // Ensure that version negotiation packets we send have at least two
+      // versions. This guarantees that, under all circumstances, all QUIC
+      // packets we send are at least 14 bytes long.
+      wire_versions = {QuicVersionReservedForNegotiation(),
+                       QuicVersionReservedForNegotiation()};
+    } else {
+      // This is not uniformely distributed but is acceptable since no security
+      // depends on this randomness.
+      size_t version_index = 0;
+      const bool disable_randomness =
+          GetQuicFlag(FLAGS_quic_disable_version_negotiation_grease_randomness);
+      if (!disable_randomness) {
+        version_index = QuicRandom::GetInstance()->RandUint64() %
+                        (wire_versions.size() + 1);
+      }
+      wire_versions.insert(wire_versions.begin() + version_index,
+                           QuicVersionReservedForNegotiation());
+    }
+  }
   if (ietf_quic) {
-    return BuildIetfVersionNegotiationPacket(server_connection_id,
-                                             client_connection_id, versions);
+    return BuildIetfVersionNegotiationPacket(
+        server_connection_id, client_connection_id, wire_versions);
   }
 
   // The GQUIC encoding does not support encoding client connection IDs.
   DCHECK(client_connection_id.IsEmpty());
 
-  DCHECK(!versions.empty());
+  DCHECK(!wire_versions.empty());
   size_t len = kPublicFlagsSize + server_connection_id.length() +
-               versions.size() * kQuicVersionSize;
+               wire_versions.size() * kQuicVersionSize;
   std::unique_ptr<char[]> buffer(new char[len]);
   QuicDataWriter writer(len, buffer.get());
 
@@ -1418,7 +1447,7 @@
     return nullptr;
   }
 
-  for (const ParsedQuicVersion& version : versions) {
+  for (const ParsedQuicVersion& version : wire_versions) {
     if (!writer.WriteUInt32(CreateQuicVersionLabel(version))) {
       return nullptr;
     }