diff --git a/rpcs3/Emu/Cell/SPUThread.cpp b/rpcs3/Emu/Cell/SPUThread.cpp
index de632f43cc..02943234b6 100644
--- a/rpcs3/Emu/Cell/SPUThread.cpp
+++ b/rpcs3/Emu/Cell/SPUThread.cpp
@@ -781,15 +781,18 @@ bool SPUThread::set_ch_value(u32 ch, u32 value)
 				if (!queue)
 				{
 					LOG_WARNING(SPU, "sys_spu_thread_send_event(spup=%d, data0=0x%x, data1=0x%x): event queue not connected", spup, (value & 0x00ffffff), data);
-					return ch_in_mbox.set_values(1, CELL_ENOTCONN), true; // TODO: check error passing
+					ch_in_mbox.set_values(1, CELL_ENOTCONN);
+					return true;
 				}
 
+				ch_in_mbox.set_values(1, CELL_OK);
+
 				if (!queue->send(SYS_SPU_THREAD_EVENT_USER_KEY, id, ((u64)spup << 32) | (value & 0x00ffffff), data))
 				{
-					return ch_in_mbox.set_values(1, CELL_EBUSY), true;
+					ch_in_mbox.set_values(1, CELL_EBUSY);
 				}
 
-				return ch_in_mbox.set_values(1, CELL_OK), true;
+				return true;
 			}
 			else if (code < 128)
 			{
@@ -838,15 +841,17 @@ bool SPUThread::set_ch_value(u32 ch, u32 value)
 					fmt::throw_exception("sys_event_flag_set_bit(value=0x%x (flag=%d)): In_MBox is not empty (%d)" HERE, value, flag, count);
 				}
 
-				if (flag > 63)
-				{
-					fmt::throw_exception("sys_event_flag_set_bit(id=%d, value=0x%x (flag=%d)): Invalid flag" HERE, data, value, flag);
-				}
-
 				LOG_TRACE(SPU, "sys_event_flag_set_bit(id=%d, value=0x%x (flag=%d))", data, value, flag);
 
+				ch_in_mbox.set_values(1, CELL_OK);
+
 				// Use the syscall to set flag
-				return ch_in_mbox.set_values(1, sys_event_flag_set(data, 1ull << flag)), true;
+				if (s32 res = sys_event_flag_set(data, 1ull << flag))
+				{
+					ch_in_mbox.set_values(1, res);
+				}
+
+				return true;
 			}
 			else if (code == 192)
 			{
@@ -860,11 +865,6 @@ bool SPUThread::set_ch_value(u32 ch, u32 value)
 					fmt::throw_exception("sys_event_flag_set_bit_impatient(value=0x%x (flag=%d)): Out_MBox is empty" HERE, value, flag);
 				}
 
-				if (flag > 63)
-				{
-					fmt::throw_exception("sys_event_flag_set_bit_impatient(id=%d, value=0x%x (flag=%d)): Invalid flag" HERE, data, value, flag);
-				}
-
 				LOG_TRACE(SPU, "sys_event_flag_set_bit_impatient(id=%d, value=0x%x (flag=%d))", data, value, flag);
 
 				// Use the syscall to set flag