diff --git a/src/libnm-core-public/nm-version-macros.h.in b/src/libnm-core-public/nm-version-macros.h.in
index fc854aef86..cb3350f19c 100644
--- a/src/libnm-core-public/nm-version-macros.h.in
+++ b/src/libnm-core-public/nm-version-macros.h.in
@@ -73,6 +73,7 @@
 #define NM_VERSION_1_38   (NM_ENCODE_VERSION (1, 38, 0))
 #define NM_VERSION_1_40   (NM_ENCODE_VERSION (1, 40, 0))
 #define NM_VERSION_1_40_4 (NM_ENCODE_VERSION (1, 40, 4))
+#define NM_VERSION_1_40_20 (NM_ENCODE_VERSION (1, 40, 20))
 
 /* For releases, NM_API_VERSION is equal to NM_VERSION.
  *
diff --git a/src/libnm-core-public/nm-version.h b/src/libnm-core-public/nm-version.h
index d9f9a12121..5b924ce620 100644
--- a/src/libnm-core-public/nm-version.h
+++ b/src/libnm-core-public/nm-version.h
@@ -347,6 +347,12 @@
 #define NM_AVAILABLE_IN_1_40_4
 #endif
 
+#if NM_VERSION_MAX_ALLOWED < NM_VERSION_1_40_20
+#define NM_AVAILABLE_IN_1_40_20 G_UNAVAILABLE(1, 40.20)
+#else
+#define NM_AVAILABLE_IN_1_40_20
+#endif
+
 /*
  * Synchronous API for calling D-Bus in libnm is deprecated. See
  * https://networkmanager.dev/docs/libnm/latest/usage.html#sync-api