diff --git a/pkgs/by-name/uu/uucp/package.nix b/pkgs/by-name/uu/uucp/package.nix
index f94b84b646d6..c32f40589ad9 100644
--- a/pkgs/by-name/uu/uucp/package.nix
+++ b/pkgs/by-name/uu/uucp/package.nix
@@ -28,6 +28,10 @@ stdenv.mkDerivation (finalAttrs: {
       --replace-fail '(void) exit (0)' '(void) (0)'
   '';
 
+  patches = [
+    ./socklen_t.patch
+  ];
+
   # Regenerate `configure`; the checked in version was generated in 2002 and
   # contains snippets like `main(){return(0);}` that modern compilers dislike.
   nativeBuildInputs = [ autoreconfHook ];
diff --git a/pkgs/by-name/uu/uucp/socklen_t.patch b/pkgs/by-name/uu/uucp/socklen_t.patch
new file mode 100644
index 000000000000..3c8f1c0f6fa4
--- /dev/null
+++ b/pkgs/by-name/uu/uucp/socklen_t.patch
@@ -0,0 +1,26 @@
+diff --git a/unix/portnm.c b/unix/portnm.c
+index 9eda4ab..019337c 100644
+--- a/unix/portnm.c
++++ b/unix/portnm.c
+@@ -32,7 +32,7 @@ zsysdep_port_name (ftcp_port)
+ 
+ #if HAVE_TCP
+   {
+-    size_t clen;
++    socklen_t clen;
+     struct sockaddr s;
+ 
+     clen = sizeof (struct sockaddr);
+diff --git a/unix/tcp.c b/unix/tcp.c
+index 1bbcec7..af52cab 100644
+--- a/unix/tcp.c
++++ b/unix/tcp.c
+@@ -395,7 +395,7 @@ ftcp_open (qconn, ibaud, fwait, fuser)
+   while (! FGOT_SIGNAL ())
+     {
+       sockaddr_storage speer;
+-      size_t clen;
++      socklen_t clen;
+       int onew;
+       pid_t ipid;
+