diff --git a/gdk/gdkversionmacros.h.in b/gdk/gdkversionmacros.h.in
index e9d788de77..0dd77749f5 100644
--- a/gdk/gdkversionmacros.h.in
+++ b/gdk/gdkversionmacros.h.in
@@ -152,6 +152,16 @@
  */
 #define GDK_VERSION_3_18        (G_ENCODE_VERSION (3, 18))
 
+/**
+ * GDK_VERSION_3_20:
+ *
+ * A macro that evaluates to the 3.20 version of GDK, in a format
+ * that can be used by the C pre-processor.
+ *
+ * Since: 3.18
+ */
+#define GDK_VERSION_3_20        (G_ENCODE_VERSION (3, 20))
+
 /* evaluates to the current stable version; for development cycles,
  * this means the next stable target
  */
@@ -364,5 +374,19 @@
 # define GDK_AVAILABLE_IN_3_18                _GDK_EXTERN
 #endif
 
+#if GDK_VERSION_MIN_REQUIRED >= GDK_VERSION_3_20
+# define GDK_DEPRECATED_IN_3_20               GDK_DEPRECATED
+# define GDK_DEPRECATED_IN_3_20_FOR(f)        GDK_DEPRECATED_FOR(f)
+#else
+# define GDK_DEPRECATED_IN_3_20               _GDK_EXTERN
+# define GDK_DEPRECATED_IN_3_20_FOR(f)        _GDK_EXTERN
+#endif
+
+#if GDK_VERSION_MAX_ALLOWED < GDK_VERSION_3_20
+# define GDK_AVAILABLE_IN_3_20                GDK_UNAVAILABLE(3, 20)
+#else
+# define GDK_AVAILABLE_IN_3_20                _GDK_EXTERN
+#endif
+
 #endif  /* __GDK_VERSION_MACROS_H__ */