diff --git a/ChangeLog.d/fix-build-netbsd.txt b/ChangeLog.d/fix-build-netbsd.txt
new file mode 100644
index 000000000000..ac768343e3e6
--- /dev/null
+++ b/ChangeLog.d/fix-build-netbsd.txt
@@ -0,0 +1,5 @@
+Bugfix
+   * Fix building library/net_sockets.c on NetBSD. NetBSD conditionals were
+     added for the backport to avoid the risk of breaking a platform. Original
+     fix contributed by Nia Alarie in #3422. Adopted for long-term support
+     branch 2.7 in #3570.
diff --git a/library/net_sockets.c b/library/net_sockets.c
index 7a56917007ee..749199a20bd8 100644
--- a/library/net_sockets.c
+++ b/library/net_sockets.c
@@ -335,8 +335,9 @@ int mbedtls_net_accept( mbedtls_net_context *bind_ctx,
 
     struct sockaddr_storage client_addr;
 
-#if defined(__socklen_t_defined) || defined(_SOCKLEN_T) ||  \
-    defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t)
+#if defined(__socklen_t_defined) || defined(_SOCKLEN_T) || \
+    defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t) || \
+    ( defined(__NetBSD__) && defined(socklen_t) )
     socklen_t n = (socklen_t) sizeof( client_addr );
     socklen_t type_len = (socklen_t) sizeof( type );
 #else