Issue 15505. unittest.installHandler and non callable signal handlers
diff --git a/Misc/NEWS b/Misc/NEWS
index 89cf9d3..8057afe 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -202,6 +202,9 @@
 Library
 -------
 
+- Issue #15505: `unittest.installHandler` no longer assumes SIGINT handler is
+  set to a callable object.
+
 - Issue #17051: Fix a memory leak in os.path.isdir() on Windows. Patch by
   Robert Xiao.