diff --git a/src/sortedcontainers/sortedset.py b/src/sortedcontainers/sortedset.py
index f2416bf..58277ad 100644
--- a/src/sortedcontainers/sortedset.py
+++ b/src/sortedcontainers/sortedset.py
@@ -394,7 +394,11 @@ def discard(self, value):
         _set = self._set
         if value in _set:
             _set.remove(value)
-            self._list.remove(value)
+            try:
+                self._list.remove(value)
+            except ValueError:
+                self._list.clear()
+                self._list.update(_set)
 
     _discard = discard
 
diff --git a/tests/test_coverage_sortedset.py b/tests/test_coverage_sortedset.py
index c432a3f..b08b4db 100644
--- a/tests/test_coverage_sortedset.py
+++ b/tests/test_coverage_sortedset.py
@@ -360,6 +360,16 @@ def test_discard():
     assert len(temp) == 97
 
 
+def test_discard_with_changed_key():
+    keys = {value: value for value in range(5)}
+    temp = SortedSet(range(5), key=keys.__getitem__)
+    value = temp[-1]
+    keys[value] = -1
+    temp.discard(value)
+    temp._check()
+    assert value not in temp
+
+
 def test_index():
     temp = SortedSet(range(100))
     temp._reset(7)