diff --git a/omaha_request_builder_xml.cc b/omaha_request_builder_xml.cc
index 823894e..8439b42 100644
--- a/omaha_request_builder_xml.cc
+++ b/omaha_request_builder_xml.cc
@@ -37,6 +37,7 @@
 namespace chromeos_update_engine {
 
 const int kNeverPinged = -1;
+const char kNoVersion[] = "0.0.0.0";
 
 bool XmlEncode(const string& input, string* output) {
   if (std::find_if(input.begin(), input.end(), [](const char c) {
@@ -131,7 +132,7 @@
       // sent for this new version with a previous updatecheck.
       string prev_version;
       if (!prefs_->GetString(kPrefsPreviousVersion, &prev_version)) {
-        prev_version = "0.0.0.0";
+        prev_version = kNoVersion;
       }
       // We only store a non-empty previous version value after a successful
       // update in the previous boot. After reporting it back to the server,
@@ -142,7 +143,7 @@
             "previousversion=\"%s\"></event>\n",
             OmahaEvent::kTypeRebootedAfterUpdate,
             OmahaEvent::kResultSuccess,
-            XmlEncodeWithDefault(prev_version, "0.0.0.0").c_str());
+            XmlEncodeWithDefault(prev_version, kNoVersion).c_str());
         LOG_IF(WARNING, !prefs_->SetString(kPrefsPreviousVersion, ""))
             << "Unable to reset the previous version.";
       }
@@ -219,11 +220,11 @@
   if (params_->ShouldPowerwash()) {
     LOG(INFO) << "Passing OS version as 0.0.0.0 as we are set to powerwash "
               << "on downgrading to the version in the more stable channel";
-    app_versions = "version=\"0.0.0.0\" from_version=\"" +
-                   XmlEncodeWithDefault(app_data.version, "0.0.0.0") + "\" ";
+    app_versions = "version=\"" + string(kNoVersion) + "\" from_version=\"" +
+                   XmlEncodeWithDefault(app_data.version, kNoVersion) + "\" ";
   } else {
     app_versions = "version=\"" +
-                   XmlEncodeWithDefault(app_data.version, "0.0.0.0") + "\" ";
+                   XmlEncodeWithDefault(app_data.version, kNoVersion) + "\" ";
   }
 
   string download_channel = params_->download_channel();
@@ -234,7 +235,8 @@
                     XmlEncodeWithDefault(params_->current_channel()) + "\" ";
   }
 
-  string delta_okay_str = params_->delta_okay() ? "true" : "false";
+  string delta_okay_str =
+      params_->delta_okay() && !params_->is_install() ? "true" : "false";
 
   // If install_date_days is not set (e.g. its value is -1 ), don't
   // include the attribute.
@@ -382,7 +384,7 @@
   for (const auto& dlc_module_id : params_->dlc_module_ids()) {
     OmahaAppData dlc_module_app = {
         .id = params_->GetAppId() + "_" + dlc_module_id,
-        .version = params_->app_version(),
+        .version = params_->is_install() ? kNoVersion : params_->app_version(),
         .skip_update = false,
         .is_dlc = true};
     app_xml += GetApp(dlc_module_app);
diff --git a/omaha_request_builder_xml.h b/omaha_request_builder_xml.h
index 488be8a..d7a81d3 100644
--- a/omaha_request_builder_xml.h
+++ b/omaha_request_builder_xml.h
@@ -39,6 +39,7 @@
 namespace chromeos_update_engine {
 
 extern const int kNeverPinged;
+extern const char kNoVersion[];
 
 // This struct encapsulates the Omaha event information. For a
 // complete list of defined event types and results, see
diff --git a/omaha_request_builder_xml_unittest.cc b/omaha_request_builder_xml_unittest.cc
index ecab0e0..8cf7473 100644
--- a/omaha_request_builder_xml_unittest.cc
+++ b/omaha_request_builder_xml_unittest.cc
@@ -44,6 +44,13 @@
     return "";
   return xml.substr(val_start_pos + key_with_quotes.size(), val_size);
 }
+// Helper to find the count of substring in a string.
+static size_t CountSubstringInString(const string& str, const string& substr) {
+  size_t count = 0, pos = 0;
+  while ((pos = str.find(substr, pos ? pos + 1 : 0)) != string::npos)
+    ++count;
+  return count;
+}
 }  // namespace
 
 class OmahaRequestBuilderXmlTest : public ::testing::Test {
@@ -131,9 +138,8 @@
 }
 
 TEST_F(OmahaRequestBuilderXmlTest, GetRequestXmlRequestIdTest) {
-  OmahaEvent omaha_event;
   OmahaRequestParams omaha_request_params{&fake_system_state_};
-  OmahaRequestBuilderXml omaha_request{&omaha_event,
+  OmahaRequestBuilderXml omaha_request{nullptr,
                                        &omaha_request_params,
                                        false,
                                        false,
@@ -153,9 +159,8 @@
 
 TEST_F(OmahaRequestBuilderXmlTest, GetRequestXmlSessionIdTest) {
   const string gen_session_id = base::GenerateGUID();
-  OmahaEvent omaha_event;
   OmahaRequestParams omaha_request_params{&fake_system_state_};
-  OmahaRequestBuilderXml omaha_request{&omaha_event,
+  OmahaRequestBuilderXml omaha_request{nullptr,
                                        &omaha_request_params,
                                        false,
                                        false,
@@ -175,4 +180,74 @@
   EXPECT_EQ(gen_session_id, session_id);
 }
 
+TEST_F(OmahaRequestBuilderXmlTest, GetRequestXmlPlatformUpdateTest) {
+  OmahaRequestParams omaha_request_params{&fake_system_state_};
+  OmahaRequestBuilderXml omaha_request{nullptr,
+                                       &omaha_request_params,
+                                       false,
+                                       false,
+                                       0,
+                                       0,
+                                       0,
+                                       fake_system_state_.prefs(),
+                                       ""};
+  const string request_xml = omaha_request.GetRequest();
+  EXPECT_EQ(1, CountSubstringInString(request_xml, "<updatecheck"))
+      << request_xml;
+}
+
+TEST_F(OmahaRequestBuilderXmlTest, GetRequestXmlPlatformUpdateWithDlcsTest) {
+  OmahaRequestParams omaha_request_params{&fake_system_state_};
+  omaha_request_params.set_dlc_module_ids({"dlc_1", "dlc_2"});
+  OmahaRequestBuilderXml omaha_request{nullptr,
+                                       &omaha_request_params,
+                                       false,
+                                       false,
+                                       0,
+                                       0,
+                                       0,
+                                       fake_system_state_.prefs(),
+                                       ""};
+  const string request_xml = omaha_request.GetRequest();
+  EXPECT_EQ(3, CountSubstringInString(request_xml, "<updatecheck"))
+      << request_xml;
+}
+
+TEST_F(OmahaRequestBuilderXmlTest, GetRequestXmlDlcInstallationTest) {
+  OmahaRequestParams omaha_request_params{&fake_system_state_};
+  const vector<string> dlcs = {"dlc_1", "dlc_2"};
+  omaha_request_params.set_dlc_module_ids(dlcs);
+  omaha_request_params.set_is_install(true);
+  OmahaRequestBuilderXml omaha_request{nullptr,
+                                       &omaha_request_params,
+                                       false,
+                                       false,
+                                       0,
+                                       0,
+                                       0,
+                                       fake_system_state_.prefs(),
+                                       ""};
+  const string request_xml = omaha_request.GetRequest();
+  EXPECT_EQ(2, CountSubstringInString(request_xml, "<updatecheck"))
+      << request_xml;
+
+  auto FindAppId = [request_xml](size_t pos) -> size_t {
+    return request_xml.find("<app appid", pos);
+  };
+  // Skip over the Platform AppID, which is always first.
+  size_t pos = FindAppId(0);
+  for (auto&& _ : dlcs) {
+    (void)_;
+    EXPECT_NE(string::npos, (pos = FindAppId(pos + 1))) << request_xml;
+    const string dlc_app_id_version = FindAttributeKeyValueInXml(
+        request_xml.substr(pos), "version", string(kNoVersion).size());
+    EXPECT_EQ(kNoVersion, dlc_app_id_version);
+
+    const string false_str = "false";
+    const string dlc_app_id_delta_okay = FindAttributeKeyValueInXml(
+        request_xml.substr(pos), "delta_okay", false_str.length());
+    EXPECT_EQ(false_str, dlc_app_id_delta_okay);
+  }
+}
+
 }  // namespace chromeos_update_engine