diff --git a/rpcs3/Emu/Cell/PPUThread.cpp b/rpcs3/Emu/Cell/PPUThread.cpp
index 1933387e65..8c5b3adc9c 100644
--- a/rpcs3/Emu/Cell/PPUThread.cpp
+++ b/rpcs3/Emu/Cell/PPUThread.cpp
@@ -788,14 +788,11 @@ ppu_thread::ppu_thread(const ppu_thread_params& param, std::string_view name, u3
 
 	gpr[13] = param.tls_addr;
 
-	if (detached >= 0 && id != id_base)
+	if (detached >= 0)
 	{
-		// Initialize thread entry point
-		cmd_list
-		({
-		    {ppu_cmd::set_args, 2}, param.arg0, param.arg1,
-		    {ppu_cmd::opd_call, 0}, std::bit_cast<u64>(entry_func),
-		});
+		// Initialize thread args
+		gpr[3] = param.arg0;
+		gpr[4] = param.arg1;
 	}
 
 	// Trigger the scheduler
diff --git a/rpcs3/Emu/Cell/lv2/sys_interrupt.cpp b/rpcs3/Emu/Cell/lv2/sys_interrupt.cpp
index c0e52ed59e..e17abbdbf3 100644
--- a/rpcs3/Emu/Cell/lv2/sys_interrupt.cpp
+++ b/rpcs3/Emu/Cell/lv2/sys_interrupt.cpp
@@ -15,7 +15,7 @@ void lv2_int_serv::exec()
 	({
 		{ ppu_cmd::reset_stack, 0 },
 		{ ppu_cmd::set_args, 2 }, arg1, arg2,
-		{ ppu_cmd::opd_call, 0 }, std::bit_cast<u64>(thread->entry_func),
+		{ ppu_cmd::opd_call, 0 }, thread->entry_func,
 		{ ppu_cmd::sleep, 0 }
 	});
 
diff --git a/rpcs3/Emu/Cell/lv2/sys_ppu_thread.cpp b/rpcs3/Emu/Cell/lv2/sys_ppu_thread.cpp
index 07b6c8594d..078a183841 100644
--- a/rpcs3/Emu/Cell/lv2/sys_ppu_thread.cpp
+++ b/rpcs3/Emu/Cell/lv2/sys_ppu_thread.cpp
@@ -441,26 +441,37 @@ error_code sys_ppu_thread_start(ppu_thread& ppu, u32 thread_id)
 {
 	sys_ppu_thread.trace("sys_ppu_thread_start(thread_id=0x%x)", thread_id);
 
-	const auto thread = idm::get<named_thread<ppu_thread>>(thread_id, [&](ppu_thread& thread)
+	const auto thread = idm::get<named_thread<ppu_thread>>(thread_id, [&](ppu_thread& thread) -> CellError
 	{
 		if (thread.joiner == ppu_join_status::exited)
 		{
-			return false;
+			return CELL_ESRCH;
+		}
+
+		if (!thread.state.test_and_reset(cpu_flag::stop))
+		{
+			// Already started
+			return CELL_EBUSY;
 		}
 
 		lv2_obj::awake(&thread);
-		return true;
+
+		thread.cmd_list
+		({
+			{ppu_cmd::opd_call, 0}, thread.entry_func
+		});
+
+		return {};
 	});
 
-	if (!thread || !thread.ret)
+	if (!thread)
 	{
 		return CELL_ESRCH;
 	}
 
-	if (!thread->state.test_and_reset(cpu_flag::stop))
+	if (thread.ret)
 	{
-		// TODO: what happens there?
-		return CELL_EPERM;
+		return thread.ret;
 	}
 	else
 	{