Index: test/std/thread/thread.threads/thread.thread.class/thread.thread.member/detach.pass.cpp
===================================================================
--- test/std/thread/thread.threads/thread.thread.class/thread.thread.member/detach.pass.cpp
+++ test/std/thread/thread.threads/thread.thread.class/thread.thread.member/detach.pass.cpp
@@ -83,7 +83,7 @@
         assert(!t0.joinable());
         try {
             t0.detach();
-        } catch (std::system_error const& ec) {
+        } catch (std::system_error const&) {
         }
     }
 #endif