diff --git a/src/game/iw3/mp/components/events.cpp b/src/game/iw3/mp/components/events.cpp
index 4b1259a6..d0022b54 100644
--- a/src/game/iw3/mp/components/events.cpp
+++ b/src/game/iw3/mp/components/events.cpp
@@ -106,15 +106,18 @@ void Events::Load_DelayStream_Hook()
 
 Detour Events::Load_DelayStream_Detour;
 
-void Events::Scr_ShutdownSystem_Hook(unsigned __int8 sys)
+void Events::Scr_ShutdownSystem_Hook(int bComplete)
 {
-    for (size_t i = 0; i < ARRAYSIZE(vmShutdownHandlers); ++i)
+    if (bComplete)
     {
-        vmShutdownHandlers[i]();
+        for (size_t i = 0; i < ARRAYSIZE(vmShutdownHandlers); ++i)
+        {
+            vmShutdownHandlers[i]();
+        }
     }
 
     // Call original function after callbacks
-    Scr_ShutdownSystem_Detour.GetOriginal<Scr_ShutdownSystem_t>()(sys);
+    Scr_ShutdownSystem_Detour.GetOriginal<Scr_ShutdownSystem_t>()(bComplete);
 }
 
 Detour Events::Scr_ShutdownSystem_Detour;
diff --git a/src/game/iw3/mp/components/events.h b/src/game/iw3/mp/components/events.h
index 5c447f63..ee7ef1e3 100644
--- a/src/game/iw3/mp/components/events.h
+++ b/src/game/iw3/mp/components/events.h
@@ -24,7 +24,7 @@ class Events : public Module
     static void Load_DelayStream_Hook();
 
     static Detour Scr_ShutdownSystem_Detour;
-    static void Scr_ShutdownSystem_Hook(unsigned __int8 sys);
+    static void Scr_ShutdownSystem_Hook(int bComplete);
 
     static Detour Com_InitDvars_Detour;
     static void Com_InitDvars_Hook();
diff --git a/src/game/iw3/mp/symbols.h b/src/game/iw3/mp/symbols.h
index 28760762..56ccdbf8 100644
--- a/src/game/iw3/mp/symbols.h
+++ b/src/game/iw3/mp/symbols.h
@@ -486,7 +486,8 @@ typedef int (*CL_ConsolePrint_AddLine_t)(int localClientNum, int channel, const
                                          unsigned int pixelWidth, char color, int flags);
 static CL_ConsolePrint_AddLine_t CL_ConsolePrint_AddLine = reinterpret_cast<CL_ConsolePrint_AddLine_t>(0x822E1EB8);
 
-typedef void (*Scr_ShutdownSystem_t)(unsigned __int8 sys);
+// TU4 omits the sys argument; only bComplete remains.
+typedef void (*Scr_ShutdownSystem_t)(int bComplete);
 static Scr_ShutdownSystem_t Scr_ShutdownSystem = reinterpret_cast<Scr_ShutdownSystem_t>(0x82211FD0);
 
 typedef void (*Com_InitDvars_t)();
diff --git a/src/game/t4/mp/components/events.cpp b/src/game/t4/mp/components/events.cpp
index 5ae4a602..59774f3d 100644
--- a/src/game/t4/mp/components/events.cpp
+++ b/src/game/t4/mp/components/events.cpp
@@ -57,10 +57,10 @@ void Events::Cmd_Init_Hook()
 
 Detour Events::Cmd_Init_Detour;
 
-void *Events::Scr_ShutdownSystem_Hook(scriptInstance_t inst, int sys, int bComplete)
+void *Events::Scr_ShutdownSystem_Hook(scriptInstance_t inst, scrSystem_t sys, int bComplete)
 {
-    // These handlers own server script state.
-    if (inst == SCRIPTINSTANCE_SERVER)
+    // These handlers own server script state and run only on complete shutdowns.
+    if (inst == SCRIPTINSTANCE_SERVER && bComplete)
     {
         for (size_t i = 0; i < ARRAYSIZE(vmShutdownHandlers); ++i)
         {
diff --git a/src/game/t4/mp/components/events.h b/src/game/t4/mp/components/events.h
index 152a93e5..26b5d637 100644
--- a/src/game/t4/mp/components/events.h
+++ b/src/game/t4/mp/components/events.h
@@ -20,7 +20,7 @@ class Events : public Module
     static void Cmd_Init_Hook();
 
     static Detour Scr_ShutdownSystem_Detour;
-    static void *Scr_ShutdownSystem_Hook(scriptInstance_t inst, int sys, int bComplete);
+    static void *Scr_ShutdownSystem_Hook(scriptInstance_t inst, scrSystem_t sys, int bComplete);
 
     static Detour UI_Refresh_Detour;
     static int UI_Refresh_Hook(int localClientNum);
diff --git a/src/game/t4/mp/structs.h b/src/game/t4/mp/structs.h
index c1f60e25..4bc848ea 100644
--- a/src/game/t4/mp/structs.h
+++ b/src/game/t4/mp/structs.h
@@ -767,6 +767,11 @@ enum svscmd_type
     SV_CMD_RELIABLE = 0x1,
 };
 
+enum scrSystem_t : __int32
+{
+    SCR_SYS_GAME = 0x1,
+};
+
 enum scriptInstance_t : __int32
 {
     SCRIPTINSTANCE_SERVER = 0x0,
diff --git a/src/game/t4/mp/symbols.h b/src/game/t4/mp/symbols.h
index 91c16f38..c0d93a79 100644
--- a/src/game/t4/mp/symbols.h
+++ b/src/game/t4/mp/symbols.h
@@ -189,7 +189,7 @@ static auto Scr_SetClientField =
     reinterpret_cast<void (*)(gclient_s *client, int offset, scriptInstance_t inst)>(0x8220A2D0);
 static auto Scr_SetGenericField =
     reinterpret_cast<void (*)(unsigned __int8 *b, fieldtype_t type, int ofs, scriptInstance_t inst)>(0x82254E90);
-typedef void *(*Scr_ShutdownSystem_t)(scriptInstance_t inst, int sys, int bComplete);
+typedef void *(*Scr_ShutdownSystem_t)(scriptInstance_t inst, scrSystem_t sys, int bComplete);
 static Scr_ShutdownSystem_t Scr_ShutdownSystem = reinterpret_cast<Scr_ShutdownSystem_t>(0x82345388);
 
 static auto String_Parse = reinterpret_cast<int (*)(const char **p, char *out, int len)>(0x822A8680);