diff --git a/Plugins/ThreadGuard/plugins.cpp b/Plugins/ThreadGuard/plugins.cpp
index dee8b26f..d0b92899 100644
--- a/Plugins/ThreadGuard/plugins.cpp
+++ b/Plugins/ThreadGuard/plugins.cpp
@@ -42,6 +42,12 @@ void IPluginsV4::Shutdown(void)
 
 void IPluginsV4::LoadEngine(cl_enginefunc_t *pEngfuncs)
 {
+	if (g_pInterface->MetaHookAPIVersion < METAHOOK_API_VERSION)
+	{
+		g_pMetaHookAPI->SysError("MetaHookAPIVersion too low! expect %d, got %d !", METAHOOK_API_VERSION, g_pInterface->MetaHookAPIVersion);
+		return;
+	}
+
 	g_pFileSystem = g_pInterface->FileSystem;
 	g_iEngineType = g_pMetaHookAPI->GetEngineType();
 	g_dwEngineBuildnum = g_pMetaHookAPI->GetEngineBuildnum();
diff --git a/include/HLSDK/common/command.h b/include/HLSDK/common/command.h
index 178db801..cc129d41 100644
--- a/include/HLSDK/common/command.h
+++ b/include/HLSDK/common/command.h
@@ -9,14 +9,14 @@ typedef struct cmd_function_s
 	char *name;
 	xcommand_t function;
 	int flags;
-}
-cmd_function_t;
+}cmd_function_t;
 
-extern cmd_function_t *(*Cmd_GetCmdBase)(void);
-
-cmd_function_t *Cmd_FindCmd(char *cmd_name);
-xcommand_t Cmd_HookCmd(char *cmd_name, xcommand_t newfuncs);
-cmd_function_t *Cmd_FindCmdPrev(char *cmd_name);
-char *Cmd_CompleteCommand(char *partial, qboolean next);
+#if 0
+extern cmd_function_t* (*Cmd_GetCmdBase)(void);
+cmd_function_t *Cmd_FindCmd(const char *cmd_name);
+xcommand_t Cmd_HookCmd(const char *cmd_name, xcommand_t newfuncs);
+cmd_function_t *Cmd_FindCmdPrev(const char *cmd_name);
+char *Cmd_CompleteCommand(const char *partial, qboolean next);
+#endif
 
 #endif
\ No newline at end of file
diff --git a/include/metahook.h b/include/metahook.h
index ed73b8ae..468a5a67 100644
--- a/include/metahook.h
+++ b/include/metahook.h
@@ -21,6 +21,9 @@ typedef int (*pfnUserMsgHook)(const char *pszName, int iSize, void *pbuf);
 
 typedef void(*cvar_callback_t)(cvar_t *pcvar);
 
+#ifndef __HLSDK_COMMAND__
+#define __HLSDK_COMMAND__
+
 typedef void(*xcommand_t)(void);
 
 typedef struct cmd_function_s
@@ -42,6 +45,8 @@ typedef struct mh_plugininfo_s
 	size_t PluginModuleSize;
 }mh_plugininfo_t;
 
+#endif
+
 #include <cdll_export.h>
 #include <cdll_int.h>
 
@@ -427,12 +432,15 @@ void MH_Shutdown(void);
 #include <ICommandLine.h>
 #include <IRegistry.h>
 
+#define METAHOOK_API_VERSION 100
+
 typedef struct mh_interface_s
 {
 	ICommandLine *CommandLine;
 	IFileSystem *FileSystem;
 	IRegistry *Registry;
 	IFileSystem_HL25* FileSystem_HL25;
+	int MetaHookAPIVersion;
 }mh_interface_t;
 
 #include <IPlugins.h>
diff --git a/src/metahook.cpp b/src/metahook.cpp
index 2972529f..445883cf 100644
--- a/src/metahook.cpp
+++ b/src/metahook.cpp
@@ -1035,6 +1035,7 @@ void MH_LoadEngine(HMODULE hEngineModule, BlobHandle_t hBlobEngine, const char*
 	gInterface.FileSystem = g_pFileSystem;
 	gInterface.Registry = registry;
 	gInterface.FileSystem_HL25 = g_pFileSystem_HL25;
+	gInterface.MetaHookAPIVersion = METAHOOK_API_VERSION;
 
 	if (hEngineModule)
 	{