diff --git a/reapi/extra/amxmodx/scripting/include/reapi_gamedll_const.inc b/reapi/extra/amxmodx/scripting/include/reapi_gamedll_const.inc
index 6151043..8bc5eff 100644
--- a/reapi/extra/amxmodx/scripting/include/reapi_gamedll_const.inc
+++ b/reapi/extra/amxmodx/scripting/include/reapi_gamedll_const.inc
@@ -37,6 +37,7 @@
 	#define RG_CBasePlayerWeapon_DefaultDeploy RG_CBaseWeapon_DefDeploy
 	#define RG_CBasePlayerWeapon_DefaultReload RG_CBaseWeapon_DefReload
 	#define RG_CBasePlayerWeapon_DefaultShotgunReload RG_CBaseWeapon_DefShotgunReload
+	#define RG_CBasePlayer_Observer_SetMode RG_CBasePlayer_Observer_SetMod
 #endif
 
 /**
@@ -784,6 +785,12 @@ enum GamedllFunc_CBasePlayer
 	* Params:           (const this, const reason[])
 	*/
 	RG_CBasePlayer_DropIdlePlayer,
+
+	/*
+	* Description:      Called when a client attempt to change the observer mode.
+	* Params:           (const this, iMode)
+	*/
+	RG_CBasePlayer_Observer_SetMode,
 	
 	/*
 	* Description:      Called when a client emits a "pain sound" after received damage.
diff --git a/reapi/include/cssdk/dlls/regamedll_api.h b/reapi/include/cssdk/dlls/regamedll_api.h
index f24e009..7924fae 100644
--- a/reapi/include/cssdk/dlls/regamedll_api.h
+++ b/reapi/include/cssdk/dlls/regamedll_api.h
@@ -501,6 +501,10 @@ typedef IHookChainRegistryClass<void, class CBaseEntity, ULONG, Vector &, Vector
 typedef IHookChainClass<Vector &, class CBaseEntity, Vector &, Vector &, float, float, int, int, int, float, entvars_t *, bool, int> IReGameHook_CBaseEntity_FireBullets3;
 typedef IHookChainRegistryClass<Vector &, class CBaseEntity, Vector &, Vector &, float, float, int, int, int, float, entvars_t *, bool, int> IReGameHookRegistry_CBaseEntity_FireBullets3;
 
+// CBasePlayer::Observer_SetMode hook
+typedef IHookChainClass<void, class CBasePlayer, int> IReGameHook_CBasePlayer_Observer_SetMode;
+typedef IHookChainRegistryClass<void, class CBasePlayer, int> IReGameHookRegistry_CBasePlayer_Observer_SetMode;
+
 // CBasePlayer::Pain hook
 typedef IHookChainClass<void, class CBasePlayer, int, bool> IReGameHook_CBasePlayer_Pain;
 typedef IHookChainRegistryClass<void, class CBasePlayer, int, bool> IReGameHookRegistry_CBasePlayer_Pain;
@@ -639,6 +643,8 @@ public:
 	virtual IReGameHookRegistry_CBaseEntity_FireBullets *CBaseEntity_FireBullets() = 0;
 	virtual IReGameHookRegistry_CBaseEntity_FireBuckshots *CBaseEntity_FireBuckshots() = 0;
 	virtual IReGameHookRegistry_CBaseEntity_FireBullets3 *CBaseEntity_FireBullets3() = 0;
+
+	virtual IReGameHookRegistry_CBasePlayer_Observer_SetMode *CBasePlayer_Observer_SetMode() = 0;
 	
 	virtual IReGameHookRegistry_CBasePlayer_Pain *CBasePlayer_Pain() = 0;
 	virtual IReGameHookRegistry_CBasePlayer_DeathSound *CBasePlayer_DeathSound() = 0;
diff --git a/reapi/src/hook_callback.cpp b/reapi/src/hook_callback.cpp
index 1e0080a..5a030b2 100644
--- a/reapi/src/hook_callback.cpp
+++ b/reapi/src/hook_callback.cpp
@@ -1237,6 +1237,16 @@ Vector &CBaseEntity_FireBullets3(IReGameHook_CBaseEntity_FireBullets3 *chain, CB
 		shared_rand);
 }
 
+void CBasePlayer_Observer_SetMode(IReGameHook_CBasePlayer_Observer_SetMode *chain, CBasePlayer *pthis, int iMode)
+{
+	auto original = [chain](int _pthis, int _iMode)
+	{
+		chain->callNext(getPrivate<CBasePlayer>(_pthis), _iMode);
+	};
+
+	callVoidForward(RG_CBasePlayer_Observer_SetMode, original, indexOfEdict(pthis->pev), iMode);
+}
+
 int g_iClientStartSpeak, g_iClientStopSpeak;
 
 void OnClientStartSpeak(size_t clientIndex)
diff --git a/reapi/src/hook_callback.h b/reapi/src/hook_callback.h
index 06eef29..4069b52 100644
--- a/reapi/src/hook_callback.h
+++ b/reapi/src/hook_callback.h
@@ -428,6 +428,7 @@ void CBasePlayer_RemoveSpawnProtection(IReGameHook_CBasePlayer_RemoveSpawnProtec
 bool CBasePlayer_HintMessageEx(IReGameHook_CBasePlayer_HintMessageEx *chain, CBasePlayer *pthis, const char *pMessage, float duration, bool bDisplayIfPlayerDead, bool bOverride);
 void CBasePlayer_UseEmpty(IReGameHook_CBasePlayer_UseEmpty *chain, CBasePlayer *pthis);
 void CBasePlayer_DropIdlePlayer(IReGameHook_CBasePlayer_DropIdlePlayer *chain, CBasePlayer *pthis, const char *reason);
+void CBasePlayer_Observer_SetMode(IReGameHook_CBasePlayer_Observer_SetMode *chain, CBasePlayer *pthis, int iMode);
 void CBasePlayer_Pain(IReGameHook_CBasePlayer_Pain *chain, CBasePlayer *pthis, int iLastHitGroup, bool bHasArmour);
 void CBasePlayer_DeathSound(IReGameHook_CBasePlayer_DeathSound *chain, CBasePlayer *pthis);
 void CBasePlayer_JoiningThink(IReGameHook_CBasePlayer_JoiningThink *chain, CBasePlayer *pthis);
diff --git a/reapi/src/hook_list.cpp b/reapi/src/hook_list.cpp
index 9ab7d51..25b83c3 100644
--- a/reapi/src/hook_list.cpp
+++ b/reapi/src/hook_list.cpp
@@ -167,6 +167,9 @@ hook_t hooklist_player[] = {
 	DLL(CBasePlayer_HintMessageEx),
 	DLL(CBasePlayer_UseEmpty),
 	DLL(CBasePlayer_DropIdlePlayer),
+
+	DLL(CBasePlayer_Observer_SetMode),
+
 	DLL(CBasePlayer_Pain),
 	DLL(CBasePlayer_DeathSound),
 	DLL(CBasePlayer_JoiningThink),
diff --git a/reapi/src/hook_list.h b/reapi/src/hook_list.h
index d9f18db..496a230 100644
--- a/reapi/src/hook_list.h
+++ b/reapi/src/hook_list.h
@@ -192,6 +192,9 @@ enum GamedllFunc_CBasePlayer
 	RG_CBasePlayer_HintMessageEx,
 	RG_CBasePlayer_UseEmpty,
 	RG_CBasePlayer_DropIdlePlayer,
+
+	RG_CBasePlayer_Observer_SetMode,
+
 	RG_CBasePlayer_Pain,
 	RG_CBasePlayer_DeathSound,
 	RG_CBasePlayer_JoiningThink,