diff --git a/include/wlr/api.h b/include/wlr/api.h
new file mode 100644
index 000000000..1b7e45676
--- /dev/null
+++ b/include/wlr/api.h
@@ -0,0 +1,20 @@
+#ifndef WLR_API_H
+#define WLR_API_H
+
+#ifndef WLR_IMPLEMENTATION
+
+#if __STDC_VERSION__ >= 202311L
+#define WLR_DEPRECATED(msg) [[deprecated(msg)]]
+#elif defined(__GNUC__)
+#define WLR_DEPRECATED(msg) __attribute__((deprecated(msg)))
+#else
+#define WLR_DEPRECATED(msg)
+#endif
+
+#else
+
+#define WLR_DEPRECATED(msg)
+
+#endif
+
+#endif
diff --git a/meson.build b/meson.build
index b0805b0c9..fcce4b8fe 100644
--- a/meson.build
+++ b/meson.build
@@ -21,6 +21,7 @@ big_endian = target_machine.endian() == 'big'
 
 add_project_arguments([
 	'-D_POSIX_C_SOURCE=200809L',
+	'-DWLR_IMPLEMENTATION',
 	'-DWLR_USE_UNSTABLE',
 	'-DWLR_LITTLE_ENDIAN=@0@'.format(little_endian.to_int()),
 	'-DWLR_BIG_ENDIAN=@0@'.format(big_endian.to_int()),