diff --git a/Python/ceval.c b/Python/ceval.c
index d74149c..5f8b860 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -1025,6 +1025,7 @@
 			}
 			Py_FatalError("invalid argument to DUP_TOPX"
 				      " (bytecode corruption?)");
+			/* Never returns, so don't bother to set why. */
 			break;
 
 		case UNARY_POSITIVE:
@@ -1618,9 +1619,11 @@
 		case PRINT_NEWLINE:
 			if (stream == NULL || stream == Py_None) {
 				w = PySys_GetObject("stdout");
-				if (w == NULL)
+				if (w == NULL) {
 					PyErr_SetString(PyExc_RuntimeError,
 							"lost sys.stdout");
+					why = WHY_EXCEPTION;
+				}
 			}
 			if (w != NULL) {
 				Py_INCREF(w);
@@ -1837,6 +1840,7 @@
 				PyErr_Format(PyExc_SystemError,
 					     "no locals when loading %s",
 					     PyObject_REPR(w));
+				why = WHY_EXCEPTION;
 				break;
 			}
 			if (PyDict_CheckExact(v)) {
@@ -2381,7 +2385,10 @@
 			Py_DECREF(v);
 			if (x != NULL) {
 				v = POP();
-				err = PyFunction_SetClosure(x, v);
+				if (PyFunction_SetClosure(x, v) != 0) {
+					/* Can't happen unless bytecode is corrupt. */
+					why = WHY_EXCEPTION;
+				}
 				Py_DECREF(v);
 			}
 			if (x != NULL && oparg > 0) {
@@ -2395,7 +2402,11 @@
 					w = POP();
 					PyTuple_SET_ITEM(v, oparg, w);
 				}
-				err = PyFunction_SetDefaults(x, v);
+				if (PyFunction_SetDefaults(x, v) != 0) {
+					/* Can't happen unless
+                                           PyFunction_SetDefaults changes. */
+					why = WHY_EXCEPTION;
+				}
 				Py_DECREF(v);
 			}
 			PUSH(x);