diff --git a/src/as-system-info.c b/src/as-system-info.c
index 306c1093..2c64bb1c 100644
--- a/src/as-system-info.c
+++ b/src/as-system-info.c
@@ -324,6 +324,8 @@ const gchar *
 as_system_info_get_os_cid (AsSystemInfo *sysinfo)
 {
 	AsSystemInfoPrivate *priv = GET_PRIVATE (sysinfo);
+	g_autofree gchar *homepage_cid = NULL;
+	g_auto(GStrv) os_id_parts = NULL;
 
 	as_system_info_load_os_release (sysinfo, NULL);
 	if (priv->os_cid != NULL)
@@ -333,6 +335,25 @@ as_system_info_get_os_cid (AsSystemInfo *sysinfo)
 		return priv->os_cid;
 	}
 
+	homepage_cid = as_utils_dns_to_rdns (priv->os_homepage, NULL);
+	if (priv->os_id != NULL) {
+		if (homepage_cid != NULL) {
+			gsize homepage_cid_len = strlen (homepage_cid);
+
+			if (g_str_has_prefix (priv->os_id, homepage_cid) &&
+			    priv->os_id[homepage_cid_len] == '.') {
+				priv->os_cid = g_strdup (priv->os_id);
+				return priv->os_cid;
+			}
+		}
+
+		os_id_parts = g_strsplit (priv->os_id, ".", -1);
+		if (g_strv_length (os_id_parts) >= 3 && as_utils_is_tld (os_id_parts[0])) {
+			priv->os_cid = g_strdup (priv->os_id);
+			return priv->os_cid;
+		}
+	}
+
 	priv->os_cid = as_utils_dns_to_rdns (priv->os_homepage, priv->os_id);
 	if (priv->os_cid == NULL)
 		return priv->os_id;
diff --git a/tests/samples/os-release-rdns-home-match b/tests/samples/os-release-rdns-home-match
new file mode 100644
index 00000000..6fdc302f
--- /dev/null
+++ b/tests/samples/os-release-rdns-home-match
@@ -0,0 +1,3 @@
+NAME="Freedesktop SDK"
+ID=org.freedesktop.platform
+HOME_URL="https://freedesktop.org"
diff --git a/tests/samples/os-release-rdns-home-match-unknown-tld b/tests/samples/os-release-rdns-home-match-unknown-tld
new file mode 100644
index 00000000..909fc8b6
--- /dev/null
+++ b/tests/samples/os-release-rdns-home-match-unknown-tld
@@ -0,0 +1,3 @@
+NAME="Freedesktop Test SDK"
+ID=invalid.freedesktop.platform
+HOME_URL="https://freedesktop.invalid"
diff --git a/tests/samples/os-release-rdns-home-mismatch b/tests/samples/os-release-rdns-home-mismatch
new file mode 100644
index 00000000..b0c1a5d6
--- /dev/null
+++ b/tests/samples/os-release-rdns-home-mismatch
@@ -0,0 +1,3 @@
+NAME="Example OS"
+ID=org.example.platform
+HOME_URL="https://project.example.com"
diff --git a/tests/samples/os-release-rdns-home-prefix-collision b/tests/samples/os-release-rdns-home-prefix-collision
new file mode 100644
index 00000000..ffd93cae
--- /dev/null
+++ b/tests/samples/os-release-rdns-home-prefix-collision
@@ -0,0 +1,3 @@
+NAME="Freedesktop Prefix Collision Test SDK"
+ID=invalid.freedesktopx.platform
+HOME_URL="https://freedesktop.invalid"
diff --git a/tests/test-basics.c b/tests/test-basics.c
index 2feabb45..13ab373e 100644
--- a/tests/test-basics.c
+++ b/tests/test-basics.c
@@ -1216,7 +1216,15 @@ test_system_info (void)
 {
 	g_autoptr(AsSystemInfo) sysinfo_tmpl = NULL;
 	g_autoptr(AsSystemInfo) sysinfo = as_system_info_new ();
+	g_autoptr(AsSystemInfo) sysinfo_rdns_home_match = as_system_info_new ();
+	g_autoptr(AsSystemInfo) sysinfo_rdns_home_match_unknown_tld = as_system_info_new ();
+	g_autoptr(AsSystemInfo) sysinfo_rdns_home_prefix_collision = as_system_info_new ();
+	g_autoptr(AsSystemInfo) sysinfo_rdns_home_mismatch = as_system_info_new ();
 	g_autofree gchar *osrelease_fname = NULL;
+	g_autofree gchar *osrelease_rdns_home_match_fname = NULL;
+	g_autofree gchar *osrelease_rdns_home_match_unknown_tld_fname = NULL;
+	g_autofree gchar *osrelease_rdns_home_prefix_collision_fname = NULL;
+	g_autofree gchar *osrelease_rdns_home_mismatch_fname = NULL;
 	g_autofree gchar *dev_name = NULL;
 	g_autoptr(GError) error = NULL;
 
@@ -1231,6 +1239,38 @@ test_system_info (void)
 	g_assert_cmpstr (as_system_info_get_os_id (sysinfo), ==, "debian");
 	g_assert_cmpstr (as_system_info_get_os_cid (sysinfo), ==, "org.debian.debian");
 
+	osrelease_rdns_home_match_fname =
+	    g_build_filename (datadir, "os-release-rdns-home-match", NULL);
+	as_system_info_load_os_release (sysinfo_rdns_home_match,
+					osrelease_rdns_home_match_fname);
+	g_assert_cmpstr (as_system_info_get_os_cid (sysinfo_rdns_home_match),
+			 ==,
+			 "org.freedesktop.platform");
+
+	osrelease_rdns_home_match_unknown_tld_fname =
+	    g_build_filename (datadir, "os-release-rdns-home-match-unknown-tld", NULL);
+	as_system_info_load_os_release (sysinfo_rdns_home_match_unknown_tld,
+					osrelease_rdns_home_match_unknown_tld_fname);
+	g_assert_cmpstr (as_system_info_get_os_cid (sysinfo_rdns_home_match_unknown_tld),
+			 ==,
+			 "invalid.freedesktop.platform");
+
+	osrelease_rdns_home_prefix_collision_fname =
+	    g_build_filename (datadir, "os-release-rdns-home-prefix-collision", NULL);
+	as_system_info_load_os_release (sysinfo_rdns_home_prefix_collision,
+					osrelease_rdns_home_prefix_collision_fname);
+	g_assert_cmpstr (as_system_info_get_os_cid (sysinfo_rdns_home_prefix_collision),
+			 ==,
+			 "invalid.freedesktop.invalid.freedesktopx.platform");
+
+	osrelease_rdns_home_mismatch_fname =
+	    g_build_filename (datadir, "os-release-rdns-home-mismatch", NULL);
+	as_system_info_load_os_release (sysinfo_rdns_home_mismatch,
+					osrelease_rdns_home_mismatch_fname);
+	g_assert_cmpstr (as_system_info_get_os_cid (sysinfo_rdns_home_mismatch),
+			 ==,
+			 "org.example.platform");
+
 #ifndef G_OS_WIN32
 	g_assert_nonnull (as_system_info_get_kernel_name (sysinfo));
 	g_assert_nonnull (as_system_info_get_kernel_version (sysinfo));