diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 3d13f5fb..f740c935 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -237,6 +237,13 @@ used and `#undef` them after.
 * Document the contents and container of a `struct wl_list` with a
   `// content.link` and `// container.list` comment.
 
+### Private fields
+
+Wrap private fields of public structures with `struct { … } WLR_PRIVATE`. This
+ensures that compositor authors don't use them by accident. Within wlroots
+`WLR_PRIVATE` is expanded to nothing, so private fields are accessed in the same
+way as public ones.
+
 ### Safety
 
 * Avoid string manipulation functions which don't take the size of the
@@ -325,12 +332,14 @@ struct wlr_compositor {
 	struct wl_global *global;
 	…
 
-	struct wl_listener display_destroy;
-
 	struct {
 		struct wl_signal new_surface;
 		struct wl_signal destroy;
 	} events;
+
+	struct {
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 ```
 
diff --git a/include/wlr/render/drm_syncobj.h b/include/wlr/render/drm_syncobj.h
index bf406d87..b847dbd2 100644
--- a/include/wlr/render/drm_syncobj.h
+++ b/include/wlr/render/drm_syncobj.h
@@ -29,9 +29,9 @@ struct wlr_drm_syncobj_timeline {
 	int drm_fd;
 	uint32_t handle;
 
-	// private state
-
-	size_t n_refs;
+	struct {
+		size_t n_refs;
+	} WLR_PRIVATE;
 };
 
 struct wlr_drm_syncobj_timeline_waiter {
@@ -39,10 +39,10 @@ struct wlr_drm_syncobj_timeline_waiter {
 		struct wl_signal ready;
 	} events;
 
-	// private state
-
-	int ev_fd;
-	struct wl_event_source *event_source;
+	struct {
+		int ev_fd;
+		struct wl_event_source *event_source;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/render/wlr_renderer.h b/include/wlr/render/wlr_renderer.h
index 4a8ccd39..debeb4e2 100644
--- a/include/wlr/render/wlr_renderer.h
+++ b/include/wlr/render/wlr_renderer.h
@@ -53,9 +53,9 @@ struct wlr_renderer {
 		bool timeline;
 	} features;
 
-	// private state
-
-	const struct wlr_renderer_impl *impl;
+	struct {
+		const struct wlr_renderer_impl *impl;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/types/wlr_alpha_modifier_v1.h b/include/wlr/types/wlr_alpha_modifier_v1.h
index e400f4e5..f70191bb 100644
--- a/include/wlr/types/wlr_alpha_modifier_v1.h
+++ b/include/wlr/types/wlr_alpha_modifier_v1.h
@@ -20,9 +20,9 @@ struct wlr_alpha_modifier_surface_v1_state {
 struct wlr_alpha_modifier_v1 {
 	struct wl_global *global;
 
-	// private state
-
-	struct wl_listener display_destroy;
+	struct {
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_alpha_modifier_v1 *wlr_alpha_modifier_v1_create(struct wl_display *display);
diff --git a/include/wlr/types/wlr_buffer.h b/include/wlr/types/wlr_buffer.h
index 9a655dd2..874edf82 100644
--- a/include/wlr/types/wlr_buffer.h
+++ b/include/wlr/types/wlr_buffer.h
@@ -148,12 +148,12 @@ struct wlr_client_buffer {
 	 */
 	struct wlr_buffer *source;
 
-	// private state
-
-	struct wl_listener source_destroy;
-	struct wl_listener renderer_destroy;
+	struct {
+		struct wl_listener source_destroy;
+		struct wl_listener renderer_destroy;
 
-	size_t n_ignore_locks;
+		size_t n_ignore_locks;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/types/wlr_compositor.h b/include/wlr/types/wlr_compositor.h
index 6ba8d8a0..291e470c 100644
--- a/include/wlr/types/wlr_compositor.h
+++ b/include/wlr/types/wlr_compositor.h
@@ -236,33 +236,33 @@ struct wlr_surface {
 	struct wlr_addon_set addons;
 	void *data;
 
-	// private state
-
-	struct wl_listener role_resource_destroy;
-
 	struct {
-		int32_t scale;
-		enum wl_output_transform transform;
-		int width, height;
-		int buffer_width, buffer_height;
-	} previous;
+		struct wl_listener role_resource_destroy;
+
+		struct {
+			int32_t scale;
+			enum wl_output_transform transform;
+			int width, height;
+			int buffer_width, buffer_height;
+		} previous;
 
-	bool unmap_commit;
+		bool unmap_commit;
 
-	bool opaque;
+		bool opaque;
 
-	bool handling_commit;
-	bool pending_rejected;
+		bool handling_commit;
+		bool pending_rejected;
 
-	int32_t preferred_buffer_scale;
-	bool preferred_buffer_transform_sent;
-	enum wl_output_transform preferred_buffer_transform;
+		int32_t preferred_buffer_scale;
+		bool preferred_buffer_transform_sent;
+		enum wl_output_transform preferred_buffer_transform;
 
-	struct wl_list synced; // wlr_surface_synced.link
-	size_t synced_len;
+		struct wl_list synced; // wlr_surface_synced.link
+		size_t synced_len;
 
-	struct wl_resource *pending_buffer_resource;
-	struct wl_listener pending_buffer_resource_destroy;
+		struct wl_resource *pending_buffer_resource;
+		struct wl_listener pending_buffer_resource_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_renderer;
diff --git a/include/wlr/types/wlr_content_type_v1.h b/include/wlr/types/wlr_content_type_v1.h
index 6fa13d9b..31c51ac4 100644
--- a/include/wlr/types/wlr_content_type_v1.h
+++ b/include/wlr/types/wlr_content_type_v1.h
@@ -23,9 +23,9 @@ struct wlr_content_type_manager_v1 {
 
 	void *data;
 
-	// private state
-
-	struct wl_listener display_destroy;
+	struct {
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_content_type_manager_v1 *wlr_content_type_manager_v1_create(
diff --git a/include/wlr/types/wlr_cursor_shape_v1.h b/include/wlr/types/wlr_cursor_shape_v1.h
index 55818c86..26048a52 100644
--- a/include/wlr/types/wlr_cursor_shape_v1.h
+++ b/include/wlr/types/wlr_cursor_shape_v1.h
@@ -28,9 +28,9 @@ struct wlr_cursor_shape_manager_v1 {
 
 	void *data;
 
-	// private state
-
-	struct wl_listener display_destroy;
+	struct {
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 enum wlr_cursor_shape_manager_v1_device_type {
diff --git a/include/wlr/types/wlr_damage_ring.h b/include/wlr/types/wlr_damage_ring.h
index 17f5bfe8..feb64777 100644
--- a/include/wlr/types/wlr_damage_ring.h
+++ b/include/wlr/types/wlr_damage_ring.h
@@ -30,9 +30,9 @@ struct wlr_damage_ring {
 	// Difference between the current buffer and the previous one
 	pixman_region32_t current;
 
-	// private state
-
-	struct wl_list buffers; // wlr_damage_ring_buffer.link
+	struct {
+		struct wl_list buffers; // wlr_damage_ring_buffer.link
+	} WLR_PRIVATE;
 };
 
 void wlr_damage_ring_init(struct wlr_damage_ring *ring);
diff --git a/include/wlr/types/wlr_drm.h b/include/wlr/types/wlr_drm.h
index b2a5ce5a..a256a8de 100644
--- a/include/wlr/types/wlr_drm.h
+++ b/include/wlr/types/wlr_drm.h
@@ -40,12 +40,12 @@ struct wlr_drm {
 		struct wl_signal destroy;
 	} events;
 
-	// private state
-
-	char *node_name;
-	struct wlr_drm_format_set formats;
+	struct {
+		char *node_name;
+		struct wlr_drm_format_set formats;
 
-	struct wl_listener display_destroy;
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_drm_buffer *wlr_drm_buffer_try_from_resource(
diff --git a/include/wlr/types/wlr_foreign_toplevel_management_v1.h b/include/wlr/types/wlr_foreign_toplevel_management_v1.h
index c4abcb3d..499d4038 100644
--- a/include/wlr/types/wlr_foreign_toplevel_management_v1.h
+++ b/include/wlr/types/wlr_foreign_toplevel_management_v1.h
@@ -39,10 +39,10 @@ struct wlr_foreign_toplevel_handle_v1_output {
 	struct wlr_output *output;
 	struct wlr_foreign_toplevel_handle_v1 *toplevel;
 
-	// private state
-
-	struct wl_listener output_bind;
-	struct wl_listener output_destroy;
+	struct {
+		struct wl_listener output_bind;
+		struct wl_listener output_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_foreign_toplevel_handle_v1 {
diff --git a/include/wlr/types/wlr_fractional_scale_v1.h b/include/wlr/types/wlr_fractional_scale_v1.h
index 9126360d..09214eb8 100644
--- a/include/wlr/types/wlr_fractional_scale_v1.h
+++ b/include/wlr/types/wlr_fractional_scale_v1.h
@@ -20,9 +20,9 @@ struct wlr_fractional_scale_manager_v1 {
 		struct wl_signal destroy;
 	} events;
 
-	// private state
-
-	struct wl_listener display_destroy;
+	struct {
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 void wlr_fractional_scale_v1_notify_scale(
diff --git a/include/wlr/types/wlr_idle_notify_v1.h b/include/wlr/types/wlr_idle_notify_v1.h
index 8dea0804..508c0cb7 100644
--- a/include/wlr/types/wlr_idle_notify_v1.h
+++ b/include/wlr/types/wlr_idle_notify_v1.h
@@ -19,12 +19,12 @@ struct wlr_seat;
 struct wlr_idle_notifier_v1 {
 	struct wl_global *global;
 
-	// private state
+	struct {
+		bool inhibited;
+		struct wl_list notifications; // wlr_idle_notification_v1.link
 
-	bool inhibited;
-	struct wl_list notifications; // wlr_idle_notification_v1.link
-
-	struct wl_listener display_destroy;
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 
diff --git a/include/wlr/types/wlr_layer_shell_v1.h b/include/wlr/types/wlr_layer_shell_v1.h
index 9be246e1..d46f9b9c 100644
--- a/include/wlr/types/wlr_layer_shell_v1.h
+++ b/include/wlr/types/wlr_layer_shell_v1.h
@@ -114,9 +114,9 @@ struct wlr_layer_surface_v1 {
 
 	void *data;
 
-	// private state
-
-	struct wlr_surface_synced synced;
+	struct {
+		struct wlr_surface_synced synced;
+	} WLR_PRIVATE;
 };
 
 struct wlr_layer_shell_v1 *wlr_layer_shell_v1_create(struct wl_display *display,
diff --git a/include/wlr/types/wlr_linux_dmabuf_v1.h b/include/wlr/types/wlr_linux_dmabuf_v1.h
index cf967f95..2193f914 100644
--- a/include/wlr/types/wlr_linux_dmabuf_v1.h
+++ b/include/wlr/types/wlr_linux_dmabuf_v1.h
@@ -24,9 +24,9 @@ struct wlr_dmabuf_v1_buffer {
 	struct wl_resource *resource; // can be NULL if the client destroyed it
 	struct wlr_dmabuf_attributes attributes;
 
-	// private state
-
-	struct wl_listener release;
+	struct {
+		struct wl_listener release;
+	} WLR_PRIVATE;
 };
 
 /**
@@ -55,18 +55,18 @@ struct wlr_linux_dmabuf_v1 {
 		struct wl_signal destroy;
 	} events;
 
-	// private state
-
-	struct wlr_linux_dmabuf_feedback_v1_compiled *default_feedback;
-	struct wlr_drm_format_set default_formats; // for legacy clients
-	struct wl_list surfaces; // wlr_linux_dmabuf_v1_surface.link
+	struct {
+		struct wlr_linux_dmabuf_feedback_v1_compiled *default_feedback;
+		struct wlr_drm_format_set default_formats; // for legacy clients
+		struct wl_list surfaces; // wlr_linux_dmabuf_v1_surface.link
 
-	int main_device_fd; // to sanity check FDs sent by clients, -1 if unavailable
+		int main_device_fd; // to sanity check FDs sent by clients, -1 if unavailable
 
-	struct wl_listener display_destroy;
+		struct wl_listener display_destroy;
 
-	bool (*check_dmabuf_callback)(struct wlr_dmabuf_attributes *attribs, void *data);
-	void *check_dmabuf_callback_data;
+		bool (*check_dmabuf_callback)(struct wlr_dmabuf_attributes *attribs, void *data);
+		void *check_dmabuf_callback_data;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/types/wlr_linux_drm_syncobj_v1.h b/include/wlr/types/wlr_linux_drm_syncobj_v1.h
index 02cdb42a..73335041 100644
--- a/include/wlr/types/wlr_linux_drm_syncobj_v1.h
+++ b/include/wlr/types/wlr_linux_drm_syncobj_v1.h
@@ -26,11 +26,11 @@ struct wlr_linux_drm_syncobj_surface_v1_state {
 struct wlr_linux_drm_syncobj_manager_v1 {
 	struct wl_global *global;
 
-	// private state
+	struct {
+		int drm_fd;
 
-	int drm_fd;
-
-	struct wl_listener display_destroy;
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/types/wlr_output_layer.h b/include/wlr/types/wlr_output_layer.h
index 461e13dd..af59ab8d 100644
--- a/include/wlr/types/wlr_output_layer.h
+++ b/include/wlr/types/wlr_output_layer.h
@@ -50,10 +50,10 @@ struct wlr_output_layer {
 
 	void *data;
 
-	// private state
-
-	struct wlr_fbox src_box;
-	struct wlr_box dst_box;
+	struct {
+		struct wlr_fbox src_box;
+		struct wlr_box dst_box;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/types/wlr_output_layout.h b/include/wlr/types/wlr_output_layout.h
index 40c7fb93..f2cbc637 100644
--- a/include/wlr/types/wlr_output_layout.h
+++ b/include/wlr/types/wlr_output_layout.h
@@ -36,9 +36,9 @@ struct wlr_output_layout {
 
 	void *data;
 
-	// private state
-
-	struct wl_listener display_destroy;
+	struct {
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_output_layout_output {
@@ -55,11 +55,11 @@ struct wlr_output_layout_output {
 		struct wl_signal destroy;
 	} events;
 
-	// private state
-
-	struct wlr_addon addon;
+	struct {
+		struct wlr_addon addon;
 
-	struct wl_listener commit;
+		struct wl_listener commit;
+	} WLR_PRIVATE;
 };
 
 struct wlr_output_layout *wlr_output_layout_create(struct wl_display *display);
diff --git a/include/wlr/types/wlr_output_swapchain_manager.h b/include/wlr/types/wlr_output_swapchain_manager.h
index 24a5578e..3ea9c49b 100644
--- a/include/wlr/types/wlr_output_swapchain_manager.h
+++ b/include/wlr/types/wlr_output_swapchain_manager.h
@@ -30,9 +30,9 @@ struct wlr_backend_output_state;
 struct wlr_output_swapchain_manager {
 	struct wlr_backend *backend;
 
-	// private state
-
-	struct wl_array outputs; // struct wlr_output_swapchain_manager_output
+	struct {
+		struct wl_array outputs; // struct wlr_output_swapchain_manager_output
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/types/wlr_pointer_constraints_v1.h b/include/wlr/types/wlr_pointer_constraints_v1.h
index 2b4722f7..75dddb81 100644
--- a/include/wlr/types/wlr_pointer_constraints_v1.h
+++ b/include/wlr/types/wlr_pointer_constraints_v1.h
@@ -64,13 +64,13 @@ struct wlr_pointer_constraint_v1 {
 
 	void *data;
 
-	// private state
-
-	struct wl_listener surface_commit;
-	struct wl_listener surface_destroy;
-	struct wl_listener seat_destroy;
+	struct {
+		struct wl_listener surface_commit;
+		struct wl_listener surface_destroy;
+		struct wl_listener seat_destroy;
 
-	struct wlr_surface_synced synced;
+		struct wlr_surface_synced synced;
+	} WLR_PRIVATE;
 };
 
 struct wlr_pointer_constraints_v1 {
diff --git a/include/wlr/types/wlr_scene.h b/include/wlr/types/wlr_scene.h
index bcfbc72f..dbca35e7 100644
--- a/include/wlr/types/wlr_scene.h
+++ b/include/wlr/types/wlr_scene.h
@@ -75,9 +75,9 @@ struct wlr_scene_node {
 
 	struct wlr_addon_set addons;
 
-	// private state
-
-	pixman_region32_t visible;
+	struct {
+		pixman_region32_t visible;
+	} WLR_PRIVATE;
 };
 
 enum wlr_scene_debug_damage_option {
@@ -103,16 +103,16 @@ struct wlr_scene {
 	struct wlr_linux_dmabuf_v1 *linux_dmabuf_v1;
 	struct wlr_gamma_control_manager_v1 *gamma_control_manager_v1;
 
-	// private state
-
-	struct wl_listener linux_dmabuf_v1_destroy;
-	struct wl_listener gamma_control_manager_v1_destroy;
-	struct wl_listener gamma_control_manager_v1_set_gamma;
-
-	enum wlr_scene_debug_damage_option debug_damage_option;
-	bool direct_scanout;
-	bool calculate_visibility;
-	bool highlight_transparent_region;
+	struct {
+		struct wl_listener linux_dmabuf_v1_destroy;
+		struct wl_listener gamma_control_manager_v1_destroy;
+		struct wl_listener gamma_control_manager_v1_set_gamma;
+
+		enum wlr_scene_debug_damage_option debug_damage_option;
+		bool direct_scanout;
+		bool calculate_visibility;
+		bool highlight_transparent_region;
+	} WLR_PRIVATE;
 };
 
 /** A scene-graph node displaying a single surface. */
@@ -120,19 +120,19 @@ struct wlr_scene_surface {
 	struct wlr_scene_buffer *buffer;
 	struct wlr_surface *surface;
 
-	// private state
-
-	struct wlr_box clip;
-
-	struct wlr_addon addon;
-
-	struct wl_listener outputs_update;
-	struct wl_listener output_enter;
-	struct wl_listener output_leave;
-	struct wl_listener output_sample;
-	struct wl_listener frame_done;
-	struct wl_listener surface_destroy;
-	struct wl_listener surface_commit;
+	struct {
+		struct wlr_box clip;
+
+		struct wlr_addon addon;
+
+		struct wl_listener outputs_update;
+		struct wl_listener output_enter;
+		struct wl_listener output_leave;
+		struct wl_listener output_sample;
+		struct wl_listener frame_done;
+		struct wl_listener surface_destroy;
+		struct wl_listener surface_commit;
+	} WLR_PRIVATE;
 };
 
 /** A scene-graph node displaying a solid-colored rectangle */
@@ -185,21 +185,21 @@ struct wlr_scene_buffer {
 	enum wl_output_transform transform;
 	pixman_region32_t opaque_region;
 
-	// private state
-
-	uint64_t active_outputs;
-	struct wlr_texture *texture;
-	struct wlr_linux_dmabuf_feedback_v1_init_options prev_feedback_options;
+	struct {
+		uint64_t active_outputs;
+		struct wlr_texture *texture;
+		struct wlr_linux_dmabuf_feedback_v1_init_options prev_feedback_options;
 
-	bool own_buffer;
-	int buffer_width, buffer_height;
-	bool buffer_is_opaque;
+		bool own_buffer;
+		int buffer_width, buffer_height;
+		bool buffer_is_opaque;
 
-	struct wlr_drm_syncobj_timeline *wait_timeline;
-	uint64_t wait_point;
+		struct wlr_drm_syncobj_timeline *wait_timeline;
+		uint64_t wait_point;
 
-	struct wl_listener buffer_release;
-	struct wl_listener renderer_destroy;
+		struct wl_listener buffer_release;
+		struct wl_listener renderer_destroy;
+	} WLR_PRIVATE;
 };
 
 /** A viewport for an output in the scene-graph */
@@ -217,26 +217,26 @@ struct wlr_scene_output {
 		struct wl_signal destroy;
 	} events;
 
-	// private state
-
-	pixman_region32_t pending_commit_damage;
+	struct {
+		pixman_region32_t pending_commit_damage;
 
-	uint8_t index;
-	bool prev_scanout;
+		uint8_t index;
+		bool prev_scanout;
 
-	bool gamma_lut_changed;
-	struct wlr_gamma_control_v1 *gamma_lut;
+		bool gamma_lut_changed;
+		struct wlr_gamma_control_v1 *gamma_lut;
 
-	struct wl_listener output_commit;
-	struct wl_listener output_damage;
-	struct wl_listener output_needs_frame;
+		struct wl_listener output_commit;
+		struct wl_listener output_damage;
+		struct wl_listener output_needs_frame;
 
-	struct wl_list damage_highlight_regions;
+		struct wl_list damage_highlight_regions;
 
-	struct wl_array render_list;
+		struct wl_array render_list;
 
-	struct wlr_drm_syncobj_timeline *in_timeline;
-	uint64_t in_point;
+		struct wlr_drm_syncobj_timeline *in_timeline;
+		uint64_t in_point;
+	} WLR_PRIVATE;
 };
 
 struct wlr_scene_timer {
@@ -249,12 +249,12 @@ struct wlr_scene_layer_surface_v1 {
 	struct wlr_scene_tree *tree;
 	struct wlr_layer_surface_v1 *layer_surface;
 
-	// private state
-
-	struct wl_listener tree_destroy;
-	struct wl_listener layer_surface_destroy;
-	struct wl_listener layer_surface_map;
-	struct wl_listener layer_surface_unmap;
+	struct {
+		struct wl_listener tree_destroy;
+		struct wl_listener layer_surface_destroy;
+		struct wl_listener layer_surface_map;
+		struct wl_listener layer_surface_unmap;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/types/wlr_security_context_v1.h b/include/wlr/types/wlr_security_context_v1.h
index f932a2b1..40bb7a29 100644
--- a/include/wlr/types/wlr_security_context_v1.h
+++ b/include/wlr/types/wlr_security_context_v1.h
@@ -28,11 +28,11 @@ struct wlr_security_context_manager_v1 {
 
 	void *data;
 
-	// private state
-
-	struct wl_list contexts; // wlr_security_context_v1.link
+	struct {
+		struct wl_list contexts; // wlr_security_context_v1.link
 
-	struct wl_listener display_destroy;
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_security_context_v1_state {
diff --git a/include/wlr/types/wlr_session_lock_v1.h b/include/wlr/types/wlr_session_lock_v1.h
index 058bf0d7..2e9d80a9 100644
--- a/include/wlr/types/wlr_session_lock_v1.h
+++ b/include/wlr/types/wlr_session_lock_v1.h
@@ -24,9 +24,9 @@ struct wlr_session_lock_manager_v1 {
 
 	void *data;
 
-	// private state
-
-	struct wl_listener display_destroy;
+	struct {
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_session_lock_v1 {
@@ -42,9 +42,9 @@ struct wlr_session_lock_v1 {
 
 	void *data;
 
-	// private state
-
-	bool locked_sent;
+	struct {
+		bool locked_sent;
+	} WLR_PRIVATE;
 };
 
 struct wlr_session_lock_surface_v1_state {
@@ -79,11 +79,11 @@ struct wlr_session_lock_surface_v1 {
 
 	void *data;
 
-	// private state
-
-	struct wlr_surface_synced synced;
+	struct {
+		struct wlr_surface_synced synced;
 
-	struct wl_listener output_destroy;
+		struct wl_listener output_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_session_lock_manager_v1 *wlr_session_lock_manager_v1_create(
diff --git a/include/wlr/types/wlr_shm.h b/include/wlr/types/wlr_shm.h
index 13a5ca5c..650b7ffd 100644
--- a/include/wlr/types/wlr_shm.h
+++ b/include/wlr/types/wlr_shm.h
@@ -25,12 +25,12 @@ struct wlr_renderer;
 struct wlr_shm {
 	struct wl_global *global;
 
-	// private state
+	struct {
+		uint32_t *formats;
+		size_t formats_len;
 
-	uint32_t *formats;
-	size_t formats_len;
-
-	struct wl_listener display_destroy;
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/types/wlr_single_pixel_buffer_v1.h b/include/wlr/types/wlr_single_pixel_buffer_v1.h
index 3836203f..64018a86 100644
--- a/include/wlr/types/wlr_single_pixel_buffer_v1.h
+++ b/include/wlr/types/wlr_single_pixel_buffer_v1.h
@@ -14,9 +14,9 @@
 struct wlr_single_pixel_buffer_manager_v1 {
 	struct wl_global *global;
 
-	// private state
-
-	struct wl_listener display_destroy;
+	struct {
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 
diff --git a/include/wlr/types/wlr_subcompositor.h b/include/wlr/types/wlr_subcompositor.h
index 61a2cccc..26be0295 100644
--- a/include/wlr/types/wlr_subcompositor.h
+++ b/include/wlr/types/wlr_subcompositor.h
@@ -23,9 +23,9 @@ struct wlr_subsurface_parent_state {
 	int32_t x, y;
 	struct wl_list link;
 
-	// private state
-
-	struct wlr_surface_synced *synced;
+	struct {
+		struct wlr_surface_synced *synced;
+	} WLR_PRIVATE;
 };
 
 struct wlr_subsurface {
@@ -50,9 +50,9 @@ struct wlr_subsurface {
 
 	void *data;
 
-	// private state
-
-	struct wlr_surface_synced parent_synced;
+	struct {
+		struct wlr_surface_synced parent_synced;
+	} WLR_PRIVATE;
 };
 
 struct wlr_subcompositor {
diff --git a/include/wlr/types/wlr_tearing_control_v1.h b/include/wlr/types/wlr_tearing_control_v1.h
index 76c5c600..ddcb22bc 100644
--- a/include/wlr/types/wlr_tearing_control_v1.h
+++ b/include/wlr/types/wlr_tearing_control_v1.h
@@ -30,13 +30,13 @@ struct wlr_tearing_control_v1 {
 
 	struct wlr_surface *surface;
 
-	// private state
-
-	enum wp_tearing_control_v1_presentation_hint previous;
-	struct wlr_addon addon;
-	struct wlr_surface_synced synced;
+	struct {
+		enum wp_tearing_control_v1_presentation_hint previous;
+		struct wlr_addon addon;
+		struct wlr_surface_synced synced;
 
-	struct wl_listener surface_commit;
+		struct wl_listener surface_commit;
+	} WLR_PRIVATE;
 };
 
 struct wlr_tearing_control_manager_v1 {
diff --git a/include/wlr/types/wlr_transient_seat_v1.h b/include/wlr/types/wlr_transient_seat_v1.h
index 84d419bc..b0d329fd 100644
--- a/include/wlr/types/wlr_transient_seat_v1.h
+++ b/include/wlr/types/wlr_transient_seat_v1.h
@@ -17,8 +17,9 @@ struct wlr_transient_seat_v1 {
 	struct wl_resource *resource;
 	struct wlr_seat *seat;
 
-        // private state
-	struct wl_listener seat_destroy;
+	struct {
+		struct wl_listener seat_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_transient_seat_manager_v1 {
diff --git a/include/wlr/types/wlr_xdg_activation_v1.h b/include/wlr/types/wlr_xdg_activation_v1.h
index f7b038b8..6c1d5b8a 100644
--- a/include/wlr/types/wlr_xdg_activation_v1.h
+++ b/include/wlr/types/wlr_xdg_activation_v1.h
@@ -28,14 +28,14 @@ struct wlr_xdg_activation_token_v1 {
 		struct wl_signal destroy;
 	} events;
 
-	// private state
-
-	char *token;
-	struct wl_resource *resource; // can be NULL
-	struct wl_event_source *timeout; // can be NULL
+	struct {
+		char *token;
+		struct wl_resource *resource; // can be NULL
+		struct wl_event_source *timeout; // can be NULL
 
-	struct wl_listener seat_destroy;
-	struct wl_listener surface_destroy;
+		struct wl_listener seat_destroy;
+		struct wl_listener surface_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_xdg_activation_v1 {
@@ -49,13 +49,12 @@ struct wlr_xdg_activation_v1 {
 		struct wl_signal new_token; // struct wlr_xdg_activation_token_v1
 	} events;
 
-	// private state
-
-	struct wl_display *display;
-
-	struct wl_global *global;
+	struct {
+		struct wl_display *display;
+		struct wl_global *global;
 
-	struct wl_listener display_destroy;
+		struct wl_listener display_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_xdg_activation_v1_request_activate_event {
diff --git a/include/wlr/types/wlr_xdg_decoration_v1.h b/include/wlr/types/wlr_xdg_decoration_v1.h
index f1a8bc5b..24928e91 100644
--- a/include/wlr/types/wlr_xdg_decoration_v1.h
+++ b/include/wlr/types/wlr_xdg_decoration_v1.h
@@ -54,13 +54,13 @@ struct wlr_xdg_toplevel_decoration_v1 {
 
 	void *data;
 
-	// private state
-
-	struct wl_listener toplevel_destroy;
-	struct wl_listener surface_configure;
-	struct wl_listener surface_ack_configure;
+	struct {
+		struct wl_listener toplevel_destroy;
+		struct wl_listener surface_configure;
+		struct wl_listener surface_ack_configure;
 
-	struct wlr_surface_synced synced;
+		struct wlr_surface_synced synced;
+	} WLR_PRIVATE;
 };
 
 struct wlr_xdg_decoration_manager_v1 *
diff --git a/include/wlr/types/wlr_xdg_shell.h b/include/wlr/types/wlr_xdg_shell.h
index 900d504c..723f8adf 100644
--- a/include/wlr/types/wlr_xdg_shell.h
+++ b/include/wlr/types/wlr_xdg_shell.h
@@ -110,9 +110,9 @@ struct wlr_xdg_popup {
 
 	struct wl_list grab_link; // wlr_xdg_popup_grab.popups
 
-	// private state
-
-	struct wlr_surface_synced synced;
+	struct {
+		struct wlr_surface_synced synced;
+	} WLR_PRIVATE;
 };
 
 // each seat gets a popup grab
@@ -221,9 +221,9 @@ struct wlr_xdg_toplevel {
 		struct wl_signal set_app_id;
 	} events;
 
-	// private state
-
-	struct wlr_surface_synced synced;
+	struct {
+		struct wlr_surface_synced synced;
+	} WLR_PRIVATE;
 };
 
 struct wlr_xdg_surface_configure {
@@ -304,11 +304,11 @@ struct wlr_xdg_surface {
 
 	void *data;
 
-	// private state
-
-	struct wlr_surface_synced synced;
+	struct {
+		struct wlr_surface_synced synced;
 
-	struct wl_listener role_resource_destroy;
+		struct wl_listener role_resource_destroy;
+	} WLR_PRIVATE;
 };
 
 struct wlr_xdg_toplevel_move_event {
diff --git a/include/wlr/util/addon.h b/include/wlr/util/addon.h
index c64200cf..8819acce 100644
--- a/include/wlr/util/addon.h
+++ b/include/wlr/util/addon.h
@@ -12,8 +12,9 @@
 #include <wayland-server-core.h>
 
 struct wlr_addon_set {
-	// private state
-	struct wl_list addons;
+	struct {
+		struct wl_list addons;
+	} WLR_PRIVATE;
 };
 
 struct wlr_addon;
@@ -26,9 +27,11 @@ struct wlr_addon_interface {
 
 struct wlr_addon {
 	const struct wlr_addon_interface *impl;
-	// private state
-	const void *owner;
-	struct wl_list link;
+
+	struct {
+		const void *owner;
+		struct wl_list link;
+	} WLR_PRIVATE;
 };
 
 void wlr_addon_set_init(struct wlr_addon_set *set);
diff --git a/include/wlr/xwayland/shell.h b/include/wlr/xwayland/shell.h
index da5cb990..344ac220 100644
--- a/include/wlr/xwayland/shell.h
+++ b/include/wlr/xwayland/shell.h
@@ -25,13 +25,13 @@ struct wlr_xwayland_shell_v1 {
 		struct wl_signal new_surface; // struct wlr_xwayland_surface_v1
 	} events;
 
-	// private state
-
-	struct wl_client *client;
-	struct wl_list surfaces; // wlr_xwayland_surface_v1.link
+	struct {
+		struct wl_client *client;
+		struct wl_list surfaces; // wlr_xwayland_surface_v1.link
 
-	struct wl_listener display_destroy;
-	struct wl_listener client_destroy;
+		struct wl_listener display_destroy;
+		struct wl_listener client_destroy;
+	} WLR_PRIVATE;
 };
 
 /**
@@ -41,12 +41,12 @@ struct wlr_xwayland_surface_v1 {
 	struct wlr_surface *surface;
 	uint64_t serial;
 
-	// private state
-
-	struct wl_resource *resource;
-	struct wl_list link;
-	struct wlr_xwayland_shell_v1 *shell;
-	bool added;
+	struct {
+		struct wl_resource *resource;
+		struct wl_list link;
+		struct wlr_xwayland_shell_v1 *shell;
+		bool added;
+	} WLR_PRIVATE;
 };
 
 /**
diff --git a/include/wlr/xwayland/xwayland.h b/include/wlr/xwayland/xwayland.h
index c10ce4cd..339aef0e 100644
--- a/include/wlr/xwayland/xwayland.h
+++ b/include/wlr/xwayland/xwayland.h
@@ -65,13 +65,13 @@ struct wlr_xwayland {
 
 	void *data;
 
-	// private state
-
-	struct wl_listener server_start;
-	struct wl_listener server_ready;
-	struct wl_listener server_destroy;
-	struct wl_listener seat_destroy;
-	struct wl_listener shell_destroy;
+	struct {
+		struct wl_listener server_start;
+		struct wl_listener server_ready;
+		struct wl_listener server_destroy;
+		struct wl_listener seat_destroy;
+		struct wl_listener shell_destroy;
+	} WLR_PRIVATE;
 };
 
 enum wlr_xwayland_surface_decorations {
diff --git a/meson.build b/meson.build
index fcc562c8..caee73a4 100644
--- a/meson.build
+++ b/meson.build
@@ -22,6 +22,7 @@ big_endian = target_machine.endian() == 'big'
 add_project_arguments([
 	'-D_POSIX_C_SOURCE=200809L',
 	'-DWLR_USE_UNSTABLE',
+	'-DWLR_PRIVATE=',
 	'-DWLR_LITTLE_ENDIAN=@0@'.format(little_endian.to_int()),
 	'-DWLR_BIG_ENDIAN=@0@'.format(big_endian.to_int()),
 ], language: 'c')