diff --git a/mp/src/game/shared/ff/ff_sh_gamemovement.cpp b/mp/src/game/shared/ff/ff_sh_gamemovement.cpp
index 0cf777e5..35594f82 100644
--- a/mp/src/game/shared/ff/ff_sh_gamemovement.cpp
+++ b/mp/src/game/shared/ff/ff_sh_gamemovement.cpp
@@ -589,6 +589,28 @@ void CFF_SH_GameMovement::Duck( void )
 	}
 }
 
+/** Handles speed cropping while ducking
+	Overwritten from CGameMovement
+	Purpose: Allow for TFC-style duck speed cropping
+*/
+void CFF_SH_GameMovement::HandleDuckingSpeedCrop( void )
+{
+	// in HL1/TFC, crouching altered intended movement speed even while in the air
+	// it basically makes you lose speed while air controlling at high speeds
+	if (FFDEV_TFC_CROUCH_AIRMOVEMENT && ( player->GetFlags() & FL_DUCKING ))
+	{
+		float frac = 0.33333333f;
+		mv->m_flForwardMove	*= frac;
+		mv->m_flSideMove	*= frac;
+		mv->m_flUpMove		*= frac;
+		m_iSpeedCropped		|= SPEED_CROPPED_DUCK;
+	}
+	else
+	{
+		BaseClass::HandleDuckingSpeedCrop();
+	}
+}
+
 // Expose our interface.
 // Note: There can only be one IGameMovement exposed at a time
 static CFF_SH_GameMovement g_GameMovement;
diff --git a/mp/src/game/shared/ff/ff_sh_gamemovement.h b/mp/src/game/shared/ff/ff_sh_gamemovement.h
index 1878fc65..c847b2dd 100644
--- a/mp/src/game/shared/ff/ff_sh_gamemovement.h
+++ b/mp/src/game/shared/ff/ff_sh_gamemovement.h
@@ -36,7 +36,8 @@ protected:
 	virtual bool	CheckJumpButton( void );
 
 	// Ducking
-	virtual void	Duck( void );
+	virtual void	Duck( void );
+	virtual void	HandleDuckingSpeedCrop();
 	// <--- Overwritten functions
 };
 
diff --git a/mp/src/game/shared/ff/ff_sh_vars_movement.cpp b/mp/src/game/shared/ff/ff_sh_vars_movement.cpp
index b1294e43..8e07fbab 100644
--- a/mp/src/game/shared/ff/ff_sh_vars_movement.cpp
+++ b/mp/src/game/shared/ff/ff_sh_vars_movement.cpp
@@ -4,3 +4,5 @@
 #ifdef CLIENT_DLL
 ConVar cl_jumpqueue( "cl_jumpqueue", "0", FCVAR_ARCHIVE | FCVAR_USERINFO, "Enables jump queue (have to let go and press jump in between concurrent jumps) if set to 1" );
 #endif
+
+ConVar ffdev_tfc_crouch_airmovement( "ffdev_tfc_crouch_airmovement", "0", FCVAR_REPLICATED, "Enables/disables 'slower' movement while in the air; in TFC, crouching cuts your desired movement in 1/3 even in the air" );
\ No newline at end of file
diff --git a/mp/src/game/shared/ff/ff_sh_vars_movement.h b/mp/src/game/shared/ff/ff_sh_vars_movement.h
index 66839c9f..a7d4cc1a 100644
--- a/mp/src/game/shared/ff/ff_sh_vars_movement.h
+++ b/mp/src/game/shared/ff/ff_sh_vars_movement.h
@@ -15,6 +15,9 @@ extern bool g_bMovementOptimizations;
 #define SV_TRIMPTRIGGERSPEED 550.0f
 #define SV_TRIMPTRIGGERSPEEDDOWN 50.0f
 
+extern ConVar ffdev_tfc_crouch_airmovement;
+#define FFDEV_TFC_CROUCH_AIRMOVEMENT ffdev_tfc_crouch_airmovement.GetBool()
+
 #define BHOP_CAP_SOFT 1.4f
 #define BHOP_PCFACTOR 0.65f
 #define BHOP_CAP_HARD 1.8f