diff --git a/.config/linux/system/module/common/Environment.nix b/.config/linux/system/module/common/Environment.nix
index 48994f8..2cb018f 100644
--- a/.config/linux/system/module/common/Environment.nix
+++ b/.config/linux/system/module/common/Environment.nix
@@ -8,5 +8,8 @@
 		# Mangohud.
 		MANGOHUD = "1";
 		MANGOHUD_CONFIG = "no_display=0,hud_no_margin=1,font_size=12,toggle_hud=F1,fps_sampling_period=1000,fps_limit=165,fps_limit_method=early,af=16,vsync=3,gl_vsync=1,throttling_status=1,cpu_temp=1,gpu_temp=1,gpu_junction_temp=1,device_battery=gamepad,mouse,frame_timing=0,benchmark_percentiles=0,battery=1,battery_time=1,time=1,ram=1,vram=1,swap=1";
+
+		# Proton.
+		WINEFSYNC="1";
 	};
 }