diff --git a/core/libs/prx/libSceUlt/CMakeLists.txt b/core/libs/prx/libSceUlt/CMakeLists.txt
index e9ce2a507..c9005a3cb 100644
--- a/core/libs/prx/libSceUlt/CMakeLists.txt
+++ b/core/libs/prx/libSceUlt/CMakeLists.txt
@@ -20,7 +20,7 @@ if(BUILD_TESTING)
     target_include_directories(guest_ult_thread_tests PRIVATE ${LIBS_INCLUDE_DIR})
     target_link_libraries(guest_ult_thread_tests PRIVATE libSceUlt libc)
     configure_windows_unwind(guest_ult_thread_tests)
-    foreach(testCase IN ITEMS outstanding validation)
+    foreach(testCase IN ITEMS outstanding validation tryjoin destroy)
         add_test(NAME guest_ult_thread_${testCase} COMMAND guest_ult_thread_tests ${testCase})
         set_tests_properties(guest_ult_thread_${testCase} PROPERTIES TIMEOUT 20)
         if(WIN32)
diff --git a/core/libs/prx/libSceUlt/Export.cpp b/core/libs/prx/libSceUlt/Export.cpp
index 979033e5a..d87bd7e5f 100644
--- a/core/libs/prx/libSceUlt/Export.cpp
+++ b/core/libs/prx/libSceUlt/Export.cpp
@@ -108,7 +108,9 @@ void ReleaseQueue(UltQueueState& state) {
 
 void* APS5_VABI ulthreadRunner(void* arg) {
     auto* state = static_cast<UltUlthreadState*>(arg);
-    return reinterpret_cast<void*>(static_cast<std::intptr_t>(state->_entry(state->_arg)));
+    const auto result = state->_entry(state->_arg);
+    state->_exited.store(true, std::memory_order_release);
+    return reinterpret_cast<void*>(static_cast<std::intptr_t>(result));
 }
 
 }
@@ -489,6 +491,7 @@ int APS5_VABI sceUltUlthreadCreate(void* ulthread, const char* name, UltUlthread
     auto state = std::make_shared<UltUlthreadState>();
     state->_entry = entry;
     state->_arg = arg;
+    state->_runtime = runtime;
     {
         std::lock_guard<std::mutex> lock(gMutex);
         if (gRuntimes.find(runtime) == gRuntimes.end()) {
@@ -534,4 +537,51 @@ int APS5_VABI sceUltUlthreadJoin(void* ulthread, std::int32_t* status) {
     return ULT_OK;
 }
 
+int APS5_VABI sceUltUlthreadTryJoin(void* ulthread, std::int32_t* status) {
+    if (ulthread == nullptr) {
+        return ULT_ERROR_NULL;
+    }
+    {
+        std::lock_guard<std::mutex> lock(gMutex);
+        auto it = gUlthreads.find(ulthread);
+        if (it == gUlthreads.end()) {
+            return ULT_ERROR_STATE;
+        }
+        if (!it->second->_exited.load(std::memory_order_acquire)) {
+            return ULT_ERROR_BUSY;
+        }
+    }
+    return sceUltUlthreadJoin(ulthread, status);
+}
+
+int APS5_VABI sceUltUlthreadRuntimeDestroy(void* runtime) {
+    if (runtime == nullptr) {
+        return ULT_ERROR_NULL;
+    }
+    std::lock_guard<std::mutex> lock(gMutex);
+    auto it = gRuntimes.find(runtime);
+    if (it == gRuntimes.end()) {
+        return ULT_ERROR_STATE;
+    }
+    for (const auto& entry : gUlthreads) {
+        if (entry.second->_runtime == runtime) {
+            return ULT_ERROR_BUSY;
+        }
+    }
+    gRuntimes.erase(it);
+    return ULT_OK;
+}
+
+int APS5_VABI _sceUltUlthreadRuntimeOptParamInitialize(UltUlthreadRuntimeOptParam* optParam, std::uint32_t buildVersion) {
+    return sceUltUlthreadRuntimeOptParamInitialize(optParam, buildVersion);
+}
+
+int APS5_VABI _sceUltUlthreadRuntimeCreate(void* runtime, const char* name, std::uint32_t maxNumUlthread, std::uint32_t numWorkerThread, void* workArea, const void* optParam, std::uint32_t buildVersion) {
+    return sceUltUlthreadRuntimeCreate(runtime, name, maxNumUlthread, numWorkerThread, workArea, optParam, buildVersion);
+}
+
+int APS5_VABI _sceUltUlthreadCreate(void* ulthread, const char* name, UltUlthreadEntry entry, std::uint64_t arg, void* context, std::uint64_t sizeContext, void* runtime, const void* optParam, std::uint32_t buildVersion) {
+    return sceUltUlthreadCreate(ulthread, name, entry, arg, context, sizeContext, runtime, optParam, buildVersion);
+}
+
 }
diff --git a/core/libs/prx/libSceUlt/SceUltTypes.hpp b/core/libs/prx/libSceUlt/SceUltTypes.hpp
index 1a8a0c8d5..0a314a9d5 100644
--- a/core/libs/prx/libSceUlt/SceUltTypes.hpp
+++ b/core/libs/prx/libSceUlt/SceUltTypes.hpp
@@ -1,6 +1,7 @@
 #ifndef CORE_LIBS_PRX_LIBSCEULT_SCEULTTYPES_HPP
 #define CORE_LIBS_PRX_LIBSCEULT_SCEULTTYPES_HPP
 
+#include <atomic>
 #include <condition_variable>
 #include <cstdint>
 #include <memory>
@@ -70,6 +71,8 @@ struct UltUlthreadState {
     UltUlthreadEntry _entry = nullptr;
     std::uint64_t _arg = 0;
     Pthread _thread = nullptr;
+    void* _runtime = nullptr;
+    std::atomic<bool> _exited{false};
 };
 
 #endif
diff --git a/core/libs/tests/GuestUltThread.cpp b/core/libs/tests/GuestUltThread.cpp
index e46308a40..13ac01a59 100644
--- a/core/libs/tests/GuestUltThread.cpp
+++ b/core/libs/tests/GuestUltThread.cpp
@@ -13,6 +13,11 @@ std::uint64_t APS5_VABI sceUltUlthreadRuntimeGetWorkAreaSize(std::uint32_t, std:
 int APS5_VABI sceUltUlthreadRuntimeCreate(void*, const char*, std::uint32_t, std::uint32_t, void*, const void*, std::uint32_t);
 int APS5_VABI sceUltUlthreadCreate(void*, const char*, UltUlthreadEntry, std::uint64_t, void*, std::uint64_t, void*, const void*, std::uint32_t);
 int APS5_VABI sceUltUlthreadJoin(void*, std::int32_t*);
+int APS5_VABI sceUltUlthreadTryJoin(void*, std::int32_t*);
+int APS5_VABI sceUltUlthreadRuntimeDestroy(void*);
+int APS5_VABI _sceUltUlthreadRuntimeOptParamInitialize(void*, std::uint32_t);
+int APS5_VABI _sceUltUlthreadRuntimeCreate(void*, const char*, std::uint32_t, std::uint32_t, void*, const void*, std::uint32_t);
+int APS5_VABI _sceUltUlthreadCreate(void*, const char*, UltUlthreadEntry, std::uint64_t, void*, std::uint64_t, void*, const void*, std::uint32_t);
 }
 
 static constexpr int Ok = 0;
@@ -85,10 +90,55 @@ static void Validation() {
     CHECK(sceUltUlthreadRuntimeGetWorkAreaSize(1, 1) == 256u + 16u * 1024u);
 }
 
+static void TryJoin() {
+    Runtime runtime;
+    Thread thread;
+    std::uint8_t optParam[128];
+    std::memset(optParam, 0xff, sizeof(optParam));
+    CHECK(_sceUltUlthreadRuntimeOptParamInitialize(nullptr, 0) == Null);
+    CHECK(_sceUltUlthreadRuntimeOptParamInitialize(optParam, 0) == Ok && optParam[0] == 0);
+    CHECK(_sceUltUlthreadRuntimeCreate(&runtime, "runtime", 1, 1, nullptr, nullptr, 0) == Ok);
+    CHECK(_sceUltUlthreadCreate(&thread, "parked", Parked, 0x3C, nullptr, 0, &runtime, nullptr, 0) == Ok);
+    while (!gStarted.load(std::memory_order_acquire)) std::this_thread::yield();
+
+    std::int32_t status = 0;
+    const int running = sceUltUlthreadTryJoin(&thread, &status);
+    gRelease.store(true, std::memory_order_release);
+    int joined;
+    while ((joined = sceUltUlthreadTryJoin(&thread, &status)) == Busy) std::this_thread::yield();
+
+    CHECK(running == Busy);
+    CHECK(joined == Ok && status == 0x3C);
+    CHECK(sceUltUlthreadTryJoin(&thread, &status) == State);
+    CHECK(sceUltUlthreadTryJoin(nullptr, &status) == Null);
+    CHECK(sceUltUlthreadRuntimeDestroy(&runtime) == Ok);
+}
+
+static void Destroy() {
+    Runtime runtime;
+    Runtime other;
+    Thread thread;
+    CHECK(sceUltUlthreadRuntimeDestroy(nullptr) == Null);
+    CHECK(sceUltUlthreadRuntimeDestroy(&runtime) == State);
+    CHECK(_sceUltUlthreadRuntimeCreate(&runtime, "runtime", 1, 1, nullptr, nullptr, 0) == Ok);
+    CHECK(_sceUltUlthreadRuntimeCreate(&other, "other", 1, 1, nullptr, nullptr, 0) == Ok);
+    CHECK(_sceUltUlthreadCreate(&thread, "thread", Immediate, 0x11, nullptr, 0, &runtime, nullptr, 0) == Ok);
+    CHECK(sceUltUlthreadRuntimeDestroy(&other) == Ok);
+    CHECK(sceUltUlthreadRuntimeDestroy(&runtime) == Busy);
+    std::int32_t status = 0;
+    CHECK(sceUltUlthreadJoin(&thread, &status) == Ok && status == 0x11);
+    CHECK(sceUltUlthreadRuntimeDestroy(&runtime) == Ok);
+    CHECK(sceUltUlthreadRuntimeDestroy(&runtime) == State);
+    CHECK(_sceUltUlthreadCreate(&thread, "thread", Immediate, 0, nullptr, 0, &runtime, nullptr, 0) == State);
+    CHECK(sceUltFinalize() == Ok);
+}
+
 int main(int argc, char** argv) {
     CHECK(argc == 2);
     CHECK(sceUltInitialize() == Ok);
     if (std::strcmp(argv[1], "outstanding") == 0) Outstanding();
     else if (std::strcmp(argv[1], "validation") == 0) Validation();
+    else if (std::strcmp(argv[1], "tryjoin") == 0) TryJoin();
+    else if (std::strcmp(argv[1], "destroy") == 0) Destroy();
     else CHECK(false);
 }
diff --git a/docs/dev/TechnicalDebt.md b/docs/dev/TechnicalDebt.md
index 6631c12fe..4c4fb5864 100644
--- a/docs/dev/TechnicalDebt.md
+++ b/docs/dev/TechnicalDebt.md
@@ -219,6 +219,7 @@ Throughout the project, every function at every stage either **does exactly what
 - [sceKernelAddTimerEvent](../../core/libs/prx/libkernel/Equeue/Equeue.cpp) (libkernel) - `usec` is taken as the period in microseconds; re-adding an existing timer keeps its pending expiration count and restarts the period from the time of the call, where FreeBSD 12+ `filt_timertouch` clears pending expirations on `EV_ADD`; `usec == 0` fires on every wait. None of this is confirmed on a PS5 title
 - [sceRtcFormatRFC2822, sceRtcFormatRFC2822LocalTime, sceRtcFormatRFC3339LocalTime](../../core/libs/prx/libSceRtc/Export.cpp) (libSceRtc) - only shadPS4 (PS4) has bodies. A null tick returns `INVALID_POINTER` like the existing `sceRtcFormatRFC3339`, where shadPS4 formats the current time instead; offsets outside ±1439 minutes return `INVALID_VALUE` like `sceRtcFormatRFC3339`; the local-time variants use the host's offset at the given instant (shadPS4 uses `sceKernelGettimezone`, the current offset)
 - [snwprintf_s](../../core/libs/prx/libc/src/FormattingWide.cpp) (libc) - follows C11 K.3.9.1.3 with `RSIZE_MAX` assumed to be `SIZE_MAX >> 1`. A runtime-constraint violation only returns a negative value: `set_constraint_handler_s` is not exported and the console's default handler is unknown. An invalid multibyte `%s` argument is copied byte by byte instead of being reported as an encoding error, as in `vswprintf`
+- [libSceUlt ulthreads](../../core/libs/prx/libSceUlt/Export.cpp) - `_sceUltUlthreadRuntimeOptParamInitialize`, `_sceUltUlthreadRuntimeCreate` and `_sceUltUlthreadCreate` are assumed to take the same arguments as the existing exports without the underscore, including the trailing build version. `sceUltUlthreadTryJoin` is assumed to return `ULT_ERROR_BUSY` while the ulthread runs, and `sceUltUlthreadRuntimeDestroy` to return `ULT_ERROR_BUSY` while an ulthread created on the runtime is not joined. Neither error has been confirmed on PS5 hardware
 - [libSceUlt queues](../../core/libs/prx/libSceUlt/Export.cpp) - the added `sceUltQueuePop`, `sceUltQueueTryPush`, `sceUltQueueDestroy` and `sceUltQueueDataResourcePoolDestroy` signatures are inferred from the existing push/pop and object APIs. Queue destruction is assumed to reject blocked callers with `ULT_ERROR_BUSY` and otherwise discard queued data; pool exhaustion returns `ULT_ERROR_AGAIN`. These rules, alignment checks and shared slot limits have not been confirmed on PS5 hardware or a title. Non-null queue and data-pool option parameters throw because their layouts are unknown.
 - [LinuxProtFromSce](../../core/libs/prx/libkernel/DirectMemory/DirectMemory.cpp) (libkernel) - protection bits 0x100 and 0x200 are accepted and assumed not to affect host CPU access; host protection is derived only from the read, write and execute bits
 - [_sceUlobjmgrRegisterObject](../../core/libs/prx/ulobjmgr/Export.cpp) (ulobjmgr) - parameters taken from shadPS4 (PS4): a nonzero 64-bit object, a nonzero 32-bit kind and a 32-bit id output; the meaning of the first two and the PS5 signature are unverified. The id bound of `_sceUlobjmgrUnregisterObject` (below 0x4000) and the raw `EINVAL` (22) return also come from shadPS4