--- tests/socket.test	2025-04-29 17:37:07.745683933 +0200
+++ tests/socket.test	2025-04-29 17:26:42.669773969 +0200
@@ -1809,7 +1809,7 @@
 
 test socket_$af-13.1 {Testing use of shared socket between two threads} -body {
     # create a thread
-    set serverthread [thread::create -preserved [string map [list @localhost@ $localhost] {
+    set serverthread [thread::create -joinable [string map [list @localhost@ $localhost] {
         set f [socket -server accept -myaddr @localhost@ 0]
         set listen [lindex [fconfigure $f -sockname] 2]
         proc accept {s a p} {
@@ -1840,7 +1840,7 @@
         gets $s result
     }
     close $s
-    thread::release $serverthread
+    thread::join $serverthread
     append result " " [llength [thread::names]]
 } -result {hello 1} -constraints [list socket supported_$af thread]
 
Index: tests/socket.test
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