diff --git a/Lib/test/test_curses.py b/Lib/test/test_curses.py
index cdb90dbf8b6..4439fcd13c5 100644
--- a/Lib/test/test_curses.py
+++ b/Lib/test/test_curses.py
@@ -261,6 +261,10 @@ def test_resize_term(stdscr):
         if curses.LINES != lines - 1 or curses.COLS != cols + 1:
             raise RuntimeError, "Expected resizeterm to update LINES and COLS"
 
+def test_issue6243(stdscr):
+    curses.ungetch(1025)
+    stdscr.getkey()
+
 def main(stdscr):
     curses.savetty()
     try:
@@ -268,6 +272,7 @@ def main(stdscr):
         window_funcs(stdscr)
         test_userptr_without_set(stdscr)
         test_resize_term(stdscr)
+        test_issue6243(stdscr)
     finally:
         curses.resetty()
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 589590e266f..9882fad4d75 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -66,6 +66,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #6243: curses.getkey() can segfault when used with ungetch.
+  Fix by Trundle and Jerry Chen.
+
 - Issue #7597: curses.use_env() can now be called before initscr().
   Noted by Kan-Ru Chen.
 
diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index 4a77b0552ad..e2c17e1c187 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -882,14 +882,17 @@ PyCursesWindow_GetKey(PyCursesWindowObject *self, PyObject *args)
     /* getch() returns ERR in nodelay mode */
     PyErr_SetString(PyCursesError, "no input");
     return NULL;
-  } else if (rtn<=255)
+  } else if (rtn<=255) {
     return Py_BuildValue("c", rtn);
-  else
+  } else {
+    const char *knp;
 #if defined(__NetBSD__)
-    return PyString_FromString(unctrl(rtn));
+    knp = unctrl(rtn);
 #else
-    return PyString_FromString((char *)keyname(rtn));
+    knp = keyname(rtn);
 #endif
+    return PyString_FromString((knp == NULL) ? "" : knp);
+  }
 }
 
 static PyObject *