diff --git a/CHANGELOG.md b/CHANGELOG.md
index f489763c..745c4fb1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@
   - **2001 ([get_script_filename](https://library.sannybuilder.com/#/sa/CLEO/2001))**
   - **2002 ([cleo_return_with](https://library.sannybuilder.com/#/sa/CLEO/2002))**
   - **2003 ([cleo_return_fail](https://library.sannybuilder.com/#/sa/CLEO/2003))**
+  - **2004 ([allocate_memory_persistent](https://library.sannybuilder.com/#/sa/CLEO/2004))**
   - 'argument count' parameter of **0AB1 (cleo_call)** is now optional. `cleo_call @LABEL args 0` can be written as `cleo_call @LABEL`
   - 'argument count' parameter of **0AB2 (cleo_return)** is now optional. `cleo_return 0` can be written as `cleo_return`
   - opcodes **0AAB**, **0AE4**, **0AE5**, **0AE6**, **0AE7** and **0AE8** moved to the [FileSystemOperations](https://github.com/cleolibrary/CLEO5/tree/master/cleo_plugins/FileSystemOperations) plugin
diff --git a/source/CCustomOpcodeSystem.cpp b/source/CCustomOpcodeSystem.cpp
index 482dba5b..4e10d414 100644
--- a/source/CCustomOpcodeSystem.cpp
+++ b/source/CCustomOpcodeSystem.cpp
@@ -129,6 +129,7 @@ namespace CLEO
 	OpcodeResult __stdcall opcode_2001(CRunningScript* thread); // get_script_filename
 	OpcodeResult __stdcall opcode_2002(CRunningScript* thread); // cleo_return_with
 	OpcodeResult __stdcall opcode_2003(CRunningScript* thread); // cleo_return_fail
+	OpcodeResult __stdcall opcode_2004(CRunningScript* thread); // allocate_memory_persistent
 
 	typedef void(*FuncScriptDeleteDelegateT) (CRunningScript *script);
 	struct ScriptDeleteDelegate {
@@ -443,6 +444,7 @@ namespace CLEO
 		CLEO_RegisterOpcode(0x2001, opcode_2001); // get_script_filename
 		CLEO_RegisterOpcode(0x2002, opcode_2002); // cleo_return_with
 		CLEO_RegisterOpcode(0x2003, opcode_2003); // cleo_return_fail
+		CLEO_RegisterOpcode(0x2004, opcode_2004); // allocate_memory_persistent
 	}
 
 	void CCustomOpcodeSystem::Inject(CCodeInjector& inj)
@@ -2400,14 +2402,33 @@ namespace CLEO
 	//0AC9=1,free_allocated_memory %1d%
 	OpcodeResult __stdcall opcode_0AC9(CRunningScript *thread)
 	{
-		void *mem;
-		*thread >> mem;
+		void *mem; *thread >> mem;
+
+		if ((size_t)mem <= CCustomOpcodeSystem::MinValidAddress)
+		{
+			SHOW_ERROR("[0AC9] used with invalid '0x%X' pointer argument in script %s\nScript suspended.", mem, ((CCustomScript*)thread)->GetInfoStr().c_str());
+			return CCustomOpcodeSystem::ErrorSuspendScript(thread);
+		}
+
+		// allocated with 0AC8
 		auto & allocs = GetInstance().OpcodeSystem.m_pAllocations;
 		if (allocs.find(mem) != allocs.end())
 		{
 			free(mem);
 			allocs.erase(mem);
+			return OR_CONTINUE; // done
 		}
+
+		// allocated with 2004
+		auto& allocsPersist = GetInstance().OpcodeSystem.m_pAllocationsPersistent;
+		if (allocsPersist.find(mem) != allocsPersist.end())
+		{
+			free(mem);
+			allocsPersist.erase(mem);
+			return OR_CONTINUE; // done
+		}
+
+		LOG_WARNING(thread, "[0AC9] used with pointer to unknown or already freed memory in script %s", lastErrorMsg.c_str(), ((CCustomScript*)thread)->GetInfoStr().c_str());
 		return OR_CONTINUE;
 	}
 
@@ -3032,6 +3053,25 @@ namespace CLEO
 		SetScriptCondResult(thread, false);
 		return CCustomOpcodeSystem::CleoReturnGeneric(0x2003, thread, false);
 	}
+
+	//2004=2, allocate_memory_persistent size %1d% store_to %2d%
+	OpcodeResult __stdcall opcode_2004(CRunningScript* thread)
+	{
+		DWORD size; *thread >> size;
+
+		void* mem = malloc(size);
+		if (mem) 
+		{
+			DWORD oldProtect;
+			VirtualProtect(mem, size, PAGE_EXECUTE_READWRITE, &oldProtect);
+
+			GetInstance().OpcodeSystem.m_pAllocationsPersistent.insert(mem);
+		}
+
+		SetScriptCondResult(thread, mem != nullptr);
+		*thread << mem;
+		return OR_CONTINUE;
+	}
 }
 
 
diff --git a/source/CCustomOpcodeSystem.h b/source/CCustomOpcodeSystem.h
index 96913524..8d2d2ca7 100644
--- a/source/CCustomOpcodeSystem.h
+++ b/source/CCustomOpcodeSystem.h
@@ -39,6 +39,8 @@ namespace CLEO
         {
             TRACE("Last opcode executed: %04X", lastOpcode);
             TRACE("Previous opcode executed: %04X", prevOpcode);
+
+            std::for_each(m_pAllocationsPersistent.begin(), m_pAllocationsPersistent.end(), free);
         }
 
         static bool RegisterOpcode(WORD opcode, CustomOpcodeHandler callback);
@@ -53,10 +55,12 @@ namespace CLEO
         friend OpcodeResult __stdcall opcode_0AA3(CRunningScript *pScript);
         friend OpcodeResult __stdcall opcode_0AC8(CRunningScript *pScript);
         friend OpcodeResult __stdcall opcode_0AC9(CRunningScript *pScript);
+        friend OpcodeResult __stdcall opcode_2004(CRunningScript* pScript); // allocate_memory_persistent
 
         std::set<DWORD> m_hFiles;
         std::set<HMODULE> m_hNativeLibs;
         std::set<void*> m_pAllocations;
+        std::set<void*> m_pAllocationsPersistent;
 
         typedef OpcodeResult(__thiscall* _OpcodeHandler)(CRunningScript* thread, WORD opcode);