diff --git a/quic/core/quic_dispatcher.cc b/quic/core/quic_dispatcher.cc
index a1adda4..ae82fed 100644
--- a/quic/core/quic_dispatcher.cc
+++ b/quic/core/quic_dispatcher.cc
@@ -239,6 +239,8 @@
       expected_server_connection_id_length_(
           expected_server_connection_id_length),
       should_update_expected_server_connection_id_length_(false) {
+  QUIC_BUG_IF(GetSupportedVersions().empty())
+      << "Trying to create dispatcher without any supported versions";
   QUIC_DLOG(INFO) << "Created QuicDispatcher with versions: "
                   << ParsedQuicVersionVectorToString(GetSupportedVersions());
 }
diff --git a/quic/core/quic_version_manager_test.cc b/quic/core/quic_version_manager_test.cc
index 19cf5bd..2abf986 100644
--- a/quic/core/quic_version_manager_test.cc
+++ b/quic/core/quic_version_manager_test.cc
@@ -19,25 +19,33 @@
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
   SetQuicReloadableFlag(quic_enable_version_99, false);
+  SetQuicReloadableFlag(quic_supports_tls_handshake, false);
   QuicVersionManager manager(AllSupportedVersions());
 
-  EXPECT_EQ(FilterSupportedTransportVersions(AllSupportedTransportVersions()),
-            manager.GetSupportedTransportVersions());
+  ParsedQuicVersionVector expected_parsed_versions;
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_49));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_48));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_46));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_43));
 
-  EXPECT_EQ(QuicTransportVersionVector({QUIC_VERSION_50, QUIC_VERSION_49,
-                                        QUIC_VERSION_48, QUIC_VERSION_46,
-                                        QUIC_VERSION_43}),
-            manager.GetSupportedTransportVersions());
+  EXPECT_EQ(expected_parsed_versions, manager.GetSupportedVersions());
+
+  EXPECT_EQ(FilterSupportedVersions(AllSupportedVersions()),
+            manager.GetSupportedVersions());
 
   SetQuicReloadableFlag(quic_enable_version_99, true);
-  EXPECT_EQ(QuicTransportVersionVector({QUIC_VERSION_99, QUIC_VERSION_50,
-                                        QUIC_VERSION_49, QUIC_VERSION_48,
-                                        QUIC_VERSION_46, QUIC_VERSION_43}),
-            manager.GetSupportedTransportVersions());
-
-  // Ensure that all versions are now supported.
-  EXPECT_EQ(FilterSupportedTransportVersions(AllSupportedTransportVersions()),
-            manager.GetSupportedTransportVersions());
+  expected_parsed_versions.insert(
+      expected_parsed_versions.begin(),
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_99));
+  EXPECT_EQ(expected_parsed_versions, manager.GetSupportedVersions());
+  EXPECT_EQ(FilterSupportedVersions(AllSupportedVersions()),
+            manager.GetSupportedVersions());
 }
 
 }  // namespace
diff --git a/quic/core/quic_versions.cc b/quic/core/quic_versions.cc
index 4d90d78..f0a943f 100644
--- a/quic/core/quic_versions.cc
+++ b/quic/core/quic_versions.cc
@@ -226,31 +226,10 @@
   return supported_versions;
 }
 
-// TODO(nharper): Remove this function when it is no longer in use.
-QuicTransportVersionVector CurrentSupportedTransportVersions() {
-  return FilterSupportedTransportVersions(AllSupportedTransportVersions());
-}
-
 ParsedQuicVersionVector CurrentSupportedVersions() {
   return FilterSupportedVersions(AllSupportedVersions());
 }
 
-// TODO(nharper): Remove this function when it is no longer in use.
-QuicTransportVersionVector FilterSupportedTransportVersions(
-    QuicTransportVersionVector versions) {
-  ParsedQuicVersionVector parsed_versions;
-  for (QuicTransportVersion version : versions) {
-    parsed_versions.push_back(ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
-  ParsedQuicVersionVector filtered_parsed_versions =
-      FilterSupportedVersions(parsed_versions);
-  QuicTransportVersionVector filtered_versions;
-  for (ParsedQuicVersion version : filtered_parsed_versions) {
-    filtered_versions.push_back(version.transport_version);
-  }
-  return filtered_versions;
-}
-
 ParsedQuicVersionVector FilterSupportedVersions(
     ParsedQuicVersionVector versions) {
   ParsedQuicVersionVector filtered_versions;
diff --git a/quic/core/quic_versions.h b/quic/core/quic_versions.h
index 0a4022e..5b09ad6 100644
--- a/quic/core/quic_versions.h
+++ b/quic/core/quic_versions.h
@@ -236,11 +236,6 @@
 // kSupportedTransportVersions and kSupportedHandshakeProtocols.
 QUIC_EXPORT_PRIVATE ParsedQuicVersionVector AllSupportedVersions();
 
-// Returns a vector of QUIC versions from kSupportedTransportVersions which
-// exclude any versions which are disabled by flags.
-QUIC_EXPORT_PRIVATE QuicTransportVersionVector
-CurrentSupportedTransportVersions();
-
 // Returns a vector of QUIC versions that is the cartesian product of
 // kSupportedTransportVersions and kSupportedHandshakeProtocols, with any
 // versions disabled by flags excluded.
@@ -248,11 +243,6 @@
 
 // Returns a vector of QUIC versions from |versions| which exclude any versions
 // which are disabled by flags.
-QUIC_EXPORT_PRIVATE QuicTransportVersionVector
-FilterSupportedTransportVersions(QuicTransportVersionVector versions);
-
-// Returns a vector of QUIC versions from |versions| which exclude any versions
-// which are disabled by flags.
 QUIC_EXPORT_PRIVATE ParsedQuicVersionVector
 FilterSupportedVersions(ParsedQuicVersionVector versions);
 
diff --git a/quic/core/quic_versions_test.cc b/quic/core/quic_versions_test.cc
index 404aef7..5f2d7ba 100644
--- a/quic/core/quic_versions_test.cc
+++ b/quic/core/quic_versions_test.cc
@@ -253,78 +253,77 @@
     }
   }
 }
-TEST_F(QuicVersionsTest, AllSupportedTransportVersions) {
-  QuicTransportVersionVector all_versions = AllSupportedTransportVersions();
-  ASSERT_EQ(QUIC_ARRAYSIZE(kSupportedTransportVersions), all_versions.size());
-  for (size_t i = 0; i < all_versions.size(); ++i) {
-    EXPECT_EQ(kSupportedTransportVersions[i], all_versions[i]);
-  }
-}
 
-TEST_F(QuicVersionsTest, FilterSupportedTransportVersionsAllVersions) {
-  QuicTransportVersionVector all_versions = AllSupportedTransportVersions();
+TEST_F(QuicVersionsTest, FilterSupportedVersionsAllVersions) {
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
   SetQuicReloadableFlag(quic_enable_version_99, true);
-  ParsedQuicVersionVector parsed_versions;
-  for (QuicTransportVersion version : all_versions) {
-    parsed_versions.push_back(ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
-  QuicTransportVersionVector expected_versions = {
-      QUIC_VERSION_99, QUIC_VERSION_50, QUIC_VERSION_49,
-      QUIC_VERSION_48, QUIC_VERSION_46, QUIC_VERSION_43};
+  SetQuicReloadableFlag(quic_supports_tls_handshake, true);
   ParsedQuicVersionVector expected_parsed_versions;
-  for (QuicTransportVersion version : expected_versions) {
-    expected_parsed_versions.push_back(
-        ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_99));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_49));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_48));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_46));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_43));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_TLS1_3, QUIC_VERSION_99));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_TLS1_3, QUIC_VERSION_50));
 
-  ASSERT_EQ(expected_versions, FilterSupportedTransportVersions(all_versions));
-  ASSERT_EQ(expected_parsed_versions, FilterSupportedVersions(parsed_versions));
+  ASSERT_EQ(expected_parsed_versions,
+            FilterSupportedVersions(AllSupportedVersions()));
+  ASSERT_EQ(expected_parsed_versions, AllSupportedVersions());
 }
 
-TEST_F(QuicVersionsTest, FilterSupportedTransportVersionsNo99) {
-  QuicTransportVersionVector all_versions = AllSupportedTransportVersions();
+TEST_F(QuicVersionsTest, FilterSupportedVersionsNo99) {
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
   SetQuicReloadableFlag(quic_enable_version_99, false);
-  ParsedQuicVersionVector parsed_versions;
-  for (QuicTransportVersion version : all_versions) {
-    parsed_versions.push_back(ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
-  QuicTransportVersionVector expected_versions = {
-      QUIC_VERSION_50, QUIC_VERSION_49, QUIC_VERSION_48, QUIC_VERSION_46,
-      QUIC_VERSION_43};
+  SetQuicReloadableFlag(quic_supports_tls_handshake, true);
   ParsedQuicVersionVector expected_parsed_versions;
-  for (QuicTransportVersion version : expected_versions) {
-    expected_parsed_versions.push_back(
-        ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_49));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_48));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_46));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_43));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_TLS1_3, QUIC_VERSION_50));
 
-  ASSERT_EQ(expected_versions, FilterSupportedTransportVersions(all_versions));
-  ASSERT_EQ(expected_parsed_versions, FilterSupportedVersions(parsed_versions));
+  ASSERT_EQ(expected_parsed_versions,
+            FilterSupportedVersions(AllSupportedVersions()));
 }
 
-TEST_F(QuicVersionsTest, FilterSupportedTransportVersionsNoFlags) {
-  QuicTransportVersionVector all_versions = AllSupportedTransportVersions();
+TEST_F(QuicVersionsTest, FilterSupportedVersionsNoFlags) {
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
   SetQuicReloadableFlag(quic_enable_version_99, false);
-  ParsedQuicVersionVector parsed_versions;
-  for (QuicTransportVersion version : all_versions) {
-    parsed_versions.push_back(ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
-  QuicTransportVersionVector expected_versions = {
-      QUIC_VERSION_50, QUIC_VERSION_49, QUIC_VERSION_48, QUIC_VERSION_46,
-      QUIC_VERSION_43};
+  SetQuicReloadableFlag(quic_supports_tls_handshake, false);
   ParsedQuicVersionVector expected_parsed_versions;
-  for (QuicTransportVersion version : expected_versions) {
-    expected_parsed_versions.push_back(
-        ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_49));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_48));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_46));
+  expected_parsed_versions.push_back(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_43));
 
-  ASSERT_EQ(expected_versions, FilterSupportedTransportVersions(all_versions));
-  ASSERT_EQ(expected_parsed_versions, FilterSupportedVersions(parsed_versions));
+  ASSERT_EQ(expected_parsed_versions,
+            FilterSupportedVersions(AllSupportedVersions()));
 }
 
 TEST_F(QuicVersionsTest, LookUpVersionByIndex) {