diff --git a/src/env_universal_common.cpp b/src/env_universal_common.cpp
index 30d57978a..c925e29d0 100644
--- a/src/env_universal_common.cpp
+++ b/src/env_universal_common.cpp
@@ -56,7 +56,6 @@
 #include <bsd/ifaddrs.h>
 #endif  // Haiku
 
-
 /// Error message.
 #define PARSE_ERR L"Unable to parse universal variable message: '%ls'"
 
@@ -166,20 +165,30 @@ static bool append_utf8(const wcstring &input, std::string *receiver, std::strin
 
 /// Creates a file entry like "SET fish_color_cwd:FF0". Appends the result to *result (as UTF8).
 /// Returns true on success. storage may be used for temporary storage, to avoid allocations.
-static bool append_file_entry(uvar_message_type_t type, const wcstring &key_in,
+static bool append_file_entry(env_var_t::env_var_flags_t flags, const wcstring &key_in,
                               const wcstring &val_in, std::string *result, std::string *storage) {
+    namespace f3 = fish3_uvars;
     assert(storage != NULL);
     assert(result != NULL);
-    namespace f2x = fish2x_uvars;
 
     // Record the length on entry, in case we need to back up.
     bool success = true;
     const size_t result_length_on_entry = result->size();
 
-    // Append header like "SET "
-    result->append(type == uvar_message_type_t::set ? f2x::SET : f2x::SET_EXPORT);
+    // Append SETVAR header.
+    result->append(f3::SETUVAR);
     result->push_back(' ');
 
+    // Append flags.
+    if (flags & env_var_t::flag_export) {
+        result->append(f3::EXPORT);
+        result->push_back(' ');
+    }
+    if (flags & env_var_t::flag_pathvar) {
+        result->append(f3::PATH);
+        result->push_back(' ');
+    }
+
     // Append variable name like "fish_color_cwd".
     if (!valid_var_name(key_in)) {
         debug(0, L"Illegal variable name: '%ls'", key_in.c_str());
@@ -407,15 +416,16 @@ bool env_universal_t::load_from_path(const wcstring &path, callback_data_list_t
 /// Serialize the contents to a string.
 std::string env_universal_t::serialize_with_vars(const var_table_t &vars) {
     std::string storage;
-    std::string contents = SAVE_MSG;
+    std::string contents;
+    contents.append(SAVE_MSG);
+    contents.append("# VERSION: " UVARS_VERSION_3_0 "\n");
+
     for (const auto &kv : vars) {
         // Append the entry. Note that append_file_entry may fail, but that only affects one
         // variable; soldier on.
         const wcstring &key = kv.first;
         const env_var_t &var = kv.second;
-        append_file_entry(
-            var.exports() ? uvar_message_type_t::set_export : uvar_message_type_t::set, key,
-            encode_serialized(var.as_list()), &contents, &storage);
+        append_file_entry(var.get_flags(), key, encode_serialized(var.as_list()), &contents, &storage);
     }
     return contents;
 }
diff --git a/src/fish_tests.cpp b/src/fish_tests.cpp
index dfc9ede61..c591196db 100644
--- a/src/fish_tests.cpp
+++ b/src/fish_tests.cpp
@@ -2890,14 +2890,26 @@ static void test_universal() {
 
 static void test_universal_output() {
     say(L"Testing universal variable output");
+
+    const env_var_t::env_var_flags_t flag_export = env_var_t::flag_export;
+    const env_var_t::env_var_flags_t flag_pathvar = env_var_t::flag_pathvar;
+
     var_table_t vars;
     vars[L"varA"] = env_var_t(wcstring_list_t{L"ValA1", L"ValA2"}, 0);
-    vars[L"varB"] = env_var_t(wcstring_list_t{L"ValB1"}, env_var_t::flag_export);
+    vars[L"varB"] = env_var_t(wcstring_list_t{L"ValB1"}, flag_export);
+    vars[L"varC"] = env_var_t(wcstring_list_t{L"ValC1"}, 0);
+    vars[L"varD"] = env_var_t(wcstring_list_t{L"ValD1"}, flag_export | flag_pathvar);
+    vars[L"varE"] = env_var_t(wcstring_list_t{L"ValE1", L"ValE2"}, flag_pathvar);
+
     std::string text = env_universal_t::serialize_with_vars(vars);
     const char *expected =
         "# This file contains fish universal variable definitions.\n"
-        "SET varA:ValA1\\x1eValA2\n"
-        "SET_EXPORT varB:ValB1\n";
+        "# VERSION: 3.0\n"
+        "SETUVAR varA:ValA1\\x1eValA2\n"
+        "SETUVAR --export varB:ValB1\n"
+        "SETUVAR varC:ValC1\n"
+        "SETUVAR --export --path varD:ValD1\n"
+        "SETUVAR --path varE:ValE1\\x1eValE2\n";
     do_test(text == expected);
 }