diff --git a/shared/nm-glib-aux/nm-shared-utils.h b/shared/nm-glib-aux/nm-shared-utils.h
index 537b402b1c..38b100416d 100644
--- a/shared/nm-glib-aux/nm-shared-utils.h
+++ b/shared/nm-glib-aux/nm-shared-utils.h
@@ -280,6 +280,14 @@ gboolean nm_utils_ipaddr_is_normalized (int addr_family,
             return (_a < _b) ? -1 : 1; \
     } G_STMT_END
 
+/* In the general case, direct pointer comparison is undefined behavior in C.
+ * Avoid that by casting pointers to void* and then to uintptr_t. This comparison
+ * is not really meaningful, except that it provides some kind of stable sort order
+ * between pointers (that can otherwise not be compared). */
+#define NM_CMP_DIRECT_PTR(a, b) \
+	NM_CMP_DIRECT ((uintptr_t) ((void *) (a)), \
+	               (uintptr_t) ((void *) (b)))
+
 #define NM_CMP_DIRECT_MEMCMP(a, b, size) \
     NM_CMP_RETURN (memcmp ((a), (b), (size)))