diff --git a/src/gui/gui.zig b/src/gui/gui.zig
index c21905dd..af15d1ce 100644
--- a/src/gui/gui.zig
+++ b/src/gui/gui.zig
@@ -38,9 +38,13 @@ pub fn init(_allocator: Allocator) !void {
 	inline for(@typeInfo(windowlist).Struct.decls) |decl| {
 		const windowStruct = @field(windowlist, decl.name);
 		try addWindow(&windowStruct.window);
-		inline for(@typeInfo(windowStruct).Struct.decls) |_decl| {
-			if(comptime std.mem.eql(u8, _decl.name, "init")) {
-				try windowStruct.init();
+		if(@hasDecl(windowStruct, "init")) {
+			try windowStruct.init();
+		}
+		const functionNames = [_][]const u8{"render", "update", "updateSelected", "updateHovered", "onOpen", "onClose"};
+		inline for(functionNames) |function| {
+			if(@hasDecl(windowStruct, function)) {
+				@field(windowStruct.window, function ++ "Fn") = &@field(windowStruct, function);
 			}
 		}
 	}
diff --git a/src/gui/gui_component.zig b/src/gui/gui_component.zig
index dd61410b..2f2de31f 100644
--- a/src/gui/gui_component.zig
+++ b/src/gui/gui_component.zig
@@ -32,11 +32,8 @@ pub const GuiComponent = union(enum) {
 	pub fn deinit(self: GuiComponent) void {
 		switch(self) {
 			inline else => |impl| {
-				// Only call the function if it exists:
-				inline for(@typeInfo(@TypeOf(impl.*)).Struct.decls) |decl| {
-					if(comptime std.mem.eql(u8, decl.name, "deinit")) {
-						impl.deinit();
-					}
+				if(@hasDecl(@TypeOf(impl.*), "deinit")) {
+					impl.deinit();
 				}
 			}
 		}
@@ -77,11 +74,8 @@ pub const GuiComponent = union(enum) {
 	pub fn updateSelected(self: GuiComponent) void {
 		switch(self) {
 			inline else => |impl| {
-				// Only call the function if it exists:
-				inline for(@typeInfo(@TypeOf(impl.*)).Struct.decls) |decl| {
-					if(comptime std.mem.eql(u8, decl.name, "updateSelected")) {
-						impl.updateSelected();
-					}
+				if(@hasDecl(@TypeOf(impl.*), "updateSelected")) {
+					impl.updateSelected();
 				}
 			}
 		}
@@ -90,11 +84,8 @@ pub const GuiComponent = union(enum) {
 	pub fn updateHovered(self: GuiComponent, mousePosition: Vec2f) void {
 		switch(self) {
 			inline else => |impl| {
-				// Only call the function if it exists:
-				inline for(@typeInfo(@TypeOf(impl.*)).Struct.decls) |decl| {
-					if(comptime std.mem.eql(u8, decl.name, "updateHovered")) {
-						impl.updateHovered(mousePosition);
-					}
+				if(@hasDecl(@TypeOf(impl.*), "updateHovered")) {
+					impl.updateHovered(mousePosition);
 				}
 			}
 		}
@@ -103,11 +94,8 @@ pub const GuiComponent = union(enum) {
 	pub fn render(self: GuiComponent, mousePosition: Vec2f) !void {
 		switch(self) {
 			inline else => |impl| {
-				// Only call the function if it exists:
-				inline for(@typeInfo(@TypeOf(impl.*)).Struct.decls) |decl| {
-					if(comptime std.mem.eql(u8, decl.name, "render")) {
-						try impl.render(mousePosition);
-					}
+				if(@hasDecl(@TypeOf(impl.*), "render")) {
+					try impl.render(mousePosition);
 				}
 			}
 		}
@@ -116,11 +104,8 @@ pub const GuiComponent = union(enum) {
 	pub fn mainButtonPressed(self: GuiComponent, mousePosition: Vec2f) void {
 		switch(self) {
 			inline else => |impl| {
-				// Only call the function if it exists:
-				inline for(@typeInfo(@TypeOf(impl.*)).Struct.decls) |decl| {
-					if(comptime std.mem.eql(u8, decl.name, "mainButtonPressed")) {
-						impl.mainButtonPressed(mousePosition);
-					}
+				if(@hasDecl(@TypeOf(impl.*), "mainButtonPressed")) {
+					impl.mainButtonPressed(mousePosition);
 				}
 			}
 		}
@@ -129,11 +114,8 @@ pub const GuiComponent = union(enum) {
 	pub fn mainButtonReleased(self: GuiComponent, mousePosition: Vec2f) void {
 		switch(self) {
 			inline else => |impl| {
-				// Only call the function if it exists:
-				inline for(@typeInfo(@TypeOf(impl.*)).Struct.decls) |decl| {
-					if(comptime std.mem.eql(u8, decl.name, "mainButtonReleased")) {
-						impl.mainButtonReleased(mousePosition);
-					}
+				if(@hasDecl(@TypeOf(impl.*), "mainButtonReleased")) {
+					impl.mainButtonReleased(mousePosition);
 				}
 			}
 		}
diff --git a/src/gui/windows/change_name.zig b/src/gui/windows/change_name.zig
index b0ee66c0..d7252e28 100644
--- a/src/gui/windows/change_name.zig
+++ b/src/gui/windows/change_name.zig
@@ -18,8 +18,6 @@ pub var window = GuiWindow {
 	.contentSize = Vec2f{128, 256},
 	.id = "cubyz:change_name",
 	.title = "Change Name",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
 	.components = &components,
 };
 var textComponent: *TextInput = undefined;
diff --git a/src/gui/windows/chat.zig b/src/gui/windows/chat.zig
index d98fa9bb..158de27a 100644
--- a/src/gui/windows/chat.zig
+++ b/src/gui/windows/chat.zig
@@ -18,10 +18,6 @@ pub var window: GuiWindow = GuiWindow {
 	.contentSize = Vec2f{128, 256},
 	.id = "cubyz:chat",
 	.title = "Chat",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
-	.updateFn = &update,
-	.renderFn = &render,
 	.components = &components,
 	.showTitleBar = false,
 	.hasBackground = false,
diff --git a/src/gui/windows/controls.zig b/src/gui/windows/controls.zig
index 942c1db7..a5113d7b 100644
--- a/src/gui/windows/controls.zig
+++ b/src/gui/windows/controls.zig
@@ -17,9 +17,6 @@ pub var window = GuiWindow {
 	.contentSize = Vec2f{128, 256},
 	.id = "cubyz:controls",
 	.title = "Controls",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
-	.renderFn = &render,
 	.components = &components,
 };
 
diff --git a/src/gui/windows/crosshair.zig b/src/gui/windows/crosshair.zig
index 773135d1..4330832f 100644
--- a/src/gui/windows/crosshair.zig
+++ b/src/gui/windows/crosshair.zig
@@ -16,7 +16,6 @@ pub var window = GuiWindow {
 	.contentSize = Vec2f{size, size},
 	.title = "Crosshair",
 	.id = "cubyz:crosshair",
-	.renderFn = &render,
 	.showTitleBar = false,
 	.hasBackground = false,
 	.isHud = true,
diff --git a/src/gui/windows/graphics.zig b/src/gui/windows/graphics.zig
index af884dd3..88bf4da4 100644
--- a/src/gui/windows/graphics.zig
+++ b/src/gui/windows/graphics.zig
@@ -18,8 +18,6 @@ pub var window = GuiWindow {
 	.contentSize = Vec2f{128, 256},
 	.id = "cubyz:graphics",
 	.title = "Graphics",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
 	.components = &components,
 };
 
diff --git a/src/gui/windows/healthbar.zig b/src/gui/windows/healthbar.zig
index c449e16e..e2062d91 100644
--- a/src/gui/windows/healthbar.zig
+++ b/src/gui/windows/healthbar.zig
@@ -15,7 +15,6 @@ pub var window = GuiWindow {
 	.contentSize = Vec2f{128, 16},
 	.title = "Health Bar",
 	.id = "cubyz:healthbar",
-	.renderFn = &render,
 	.isHud = true,
 	.showTitleBar = false,
 	.hasBackground = false,
diff --git a/src/gui/windows/hotbar.zig b/src/gui/windows/hotbar.zig
index bad33537..d5af3738 100644
--- a/src/gui/windows/hotbar.zig
+++ b/src/gui/windows/hotbar.zig
@@ -16,9 +16,6 @@ pub var window = GuiWindow {
 	.contentSize = Vec2f{64*8, 64},
 	.title = "Hotbar",
 	.id = "cubyz:hotbar",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
-	.renderFn = &render,
 	.components = &components,
 	.isHud = true,
 	.showTitleBar = false,
diff --git a/src/gui/windows/main.zig b/src/gui/windows/main.zig
index 91926d36..3fc9363f 100644
--- a/src/gui/windows/main.zig
+++ b/src/gui/windows/main.zig
@@ -14,8 +14,6 @@ var components: [1]GuiComponent = undefined;
 pub var window = GuiWindow {
 	.contentSize = Vec2f{128, 256},
 	.id = "cubyz:main",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
 	.components = &components,
 };
 
diff --git a/src/gui/windows/multiplayer.zig b/src/gui/windows/multiplayer.zig
index fcdf2ffb..adf909b0 100644
--- a/src/gui/windows/multiplayer.zig
+++ b/src/gui/windows/multiplayer.zig
@@ -19,9 +19,6 @@ pub var window = GuiWindow {
 	.contentSize = Vec2f{128, 256},
 	.id = "cubyz:multiplayer",
 	.title = "Multiplayer",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
-	.updateFn = &update,
 	.components = &components,
 };
 
diff --git a/src/gui/windows/settings.zig b/src/gui/windows/settings.zig
index e0a10e2e..18861216 100644
--- a/src/gui/windows/settings.zig
+++ b/src/gui/windows/settings.zig
@@ -15,8 +15,6 @@ pub var window: GuiWindow = GuiWindow {
 	.contentSize = Vec2f{128, 256},
 	.id = "cubyz:settings",
 	.title = "Settings",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
 	.components = &components,
 };
 
diff --git a/src/gui/windows/sound.zig b/src/gui/windows/sound.zig
index 9e918662..2ec1b180 100644
--- a/src/gui/windows/sound.zig
+++ b/src/gui/windows/sound.zig
@@ -15,8 +15,6 @@ pub var window = GuiWindow {
 	.contentSize = Vec2f{128, 256},
 	.id = "cubyz:sound",
 	.title = "Sound TODO",
-	.onOpenFn = &onOpen,
-	.onCloseFn = &onClose,
 	.components = &components,
 };