diff --git a/Lib/test/test_with.py b/Lib/test/test_with.py
index 3007e5a..bfeb06b 100644
--- a/Lib/test/test_with.py
+++ b/Lib/test/test_with.py
@@ -503,6 +503,36 @@
 
         self.assertRaises(GeneratorExit, shouldThrow)
 
+    def testErrorsInBool(self):
+        # issue4589: __exit__ return code may raise an exception
+        # when looking at its truth value.
+
+        class cm(object):
+            def __init__(self, bool_conversion):
+                class Bool:
+                    def __nonzero__(self):
+                        return bool_conversion()
+                self.exit_result = Bool()
+            def __enter__(self):
+                return 3
+            def __exit__(self, a, b, c):
+                return self.exit_result
+
+        def trueAsBool():
+            with cm(lambda: True):
+                self.fail("Should NOT see this")
+        trueAsBool()
+
+        def falseAsBool():
+            with cm(lambda: False):
+                self.fail("Should raise")
+        self.assertRaises(AssertionError, falseAsBool)
+
+        def failAsBool():
+            with cm(lambda: 1//0):
+                self.fail("Should NOT see this")
+        self.assertRaises(ZeroDivisionError, failAsBool)
+
 
 class NonLocalFlowControlTestCase(unittest.TestCase):
 
diff --git a/Misc/NEWS b/Misc/NEWS
index effcf20..f1bc34f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and Builtins
 -----------------
 
+- Issue #4597: Fixed exception handling when the __exit__ function of a
+  context manager returns a value that cannot be converted to a bool.
+
 - Issue #4233: Changed semantic of ``_fileio.FileIO``'s ``close()`` 
   method on file objects with closefd=False. The file descriptor is still
   kept open but the file object behaves like a closed file. The ``FileIO``
diff --git a/Python/ceval.c b/Python/ceval.c
index 6eef7ef..dd1e171 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -2337,11 +2337,20 @@
 			/* XXX Not the fastest way to call it... */
 			x = PyObject_CallFunctionObjArgs(exit_func, u, v, w,
 							 NULL);
-			if (x == NULL) {
-				Py_DECREF(exit_func);
+			Py_DECREF(exit_func);
+			if (x == NULL)
 				break; /* Go to error exit */
-			}
-			if (u != Py_None && PyObject_IsTrue(x)) {
+
+			if (u != Py_None)
+				err = PyObject_IsTrue(x);
+			else
+				err = 0;
+			Py_DECREF(x);
+
+			if (err < 0)
+				break; /* Go to error exit */
+			else if (err > 0) {
+				err = 0;
 				/* There was an exception and a true return */
 				STACKADJ(-2);
 				Py_INCREF(Py_None);
@@ -2353,8 +2362,6 @@
 				/* The stack was rearranged to remove EXIT
 				   above. Let END_FINALLY do its thing */
 			}
-			Py_DECREF(x);
-			Py_DECREF(exit_func);
 			PREDICT(END_FINALLY);
 			break;
 		}