diff --git a/quic/core/quic_framer.cc b/quic/core/quic_framer.cc
index b3a5fe1..6519f57 100644
--- a/quic/core/quic_framer.cc
+++ b/quic/core/quic_framer.cc
@@ -2948,12 +2948,6 @@
       }
 
       case STOP_WAITING_FRAME: {
-        if (GetQuicReloadableFlag(quic_do_not_accept_stop_waiting) &&
-            version_.HasIetfInvariantHeader()) {
-          QUIC_RELOADABLE_FLAG_COUNT(quic_do_not_accept_stop_waiting);
-          set_detailed_error("STOP WAITING not supported in version 44+.");
-          return RaiseError(QUIC_INVALID_STOP_WAITING_DATA);
-        }
         QuicStopWaitingFrame stop_waiting_frame;
         if (!ProcessStopWaitingFrame(reader, header, &stop_waiting_frame)) {
           return RaiseError(QUIC_INVALID_STOP_WAITING_DATA);
diff --git a/quic/core/quic_framer_test.cc b/quic/core/quic_framer_test.cc
index 46cfe61..95e505b 100644
--- a/quic/core/quic_framer_test.cc
+++ b/quic/core/quic_framer_test.cc
@@ -4157,17 +4157,8 @@
 
   std::unique_ptr<QuicEncryptedPacket> encrypted(
       AssemblePacketFromFragments(fragments));
-  if (GetQuicReloadableFlag(quic_do_not_accept_stop_waiting) &&
-      framer_.version().HasIetfInvariantHeader()) {
-    EXPECT_FALSE(framer_.ProcessPacket(*encrypted));
-    EXPECT_THAT(framer_.error(), IsError(QUIC_INVALID_STOP_WAITING_DATA));
-    EXPECT_EQ("STOP WAITING not supported in version 44+.",
-              framer_.detailed_error());
-    return;
-  }
 
   EXPECT_TRUE(framer_.ProcessPacket(*encrypted));
-
   EXPECT_THAT(framer_.error(), IsQuicNoError());
   ASSERT_TRUE(visitor_.header_.get());
   EXPECT_TRUE(CheckDecryption(
@@ -4184,9 +4175,8 @@
 
 TEST_P(QuicFramerTest, InvalidNewStopWaitingFrame) {
   // The Stop Waiting frame is not in IETF QUIC
-  if (VersionHasIetfQuicFrames(version_.transport_version) ||
-      (GetQuicReloadableFlag(quic_do_not_accept_stop_waiting) &&
-       framer_.version().HasIetfInvariantHeader())) {
+  if (VersionHasIetfQuicFrames(version_.transport_version) &&
+      framer_.version().HasIetfInvariantHeader()) {
     return;
   }
   SetDecrypterLevel(ENCRYPTION_FORWARD_SECURE);