--- thread2.8.5/generic/threadCmd.c.ORIG	2019-10-04 18:43:43.000000000 +0200
+++ thread2.8.5/generic/threadCmd.c	2020-07-14 23:52:53.673184609 +0200
@@ -1687,6 +1687,7 @@
     }
 
 cleanup:
+    Tcl_Release(interp);
     Tcl_DecrRefCount(valObj);
     return rc;
 }
