diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 866e7e84ba5..29562a9a8f3 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -2678,6 +2678,8 @@ string_encode(PyStringObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, "|ss:encode", &encoding, &errors))
         return NULL;
     v = PyString_AsEncodedObject((PyObject *)self, encoding, errors);
+    if (v == NULL)
+        goto onError;
     if (!PyString_Check(v) && !PyUnicode_Check(v)) {
         PyErr_Format(PyExc_TypeError,
                      "encoder did not return a string/unicode object "
@@ -2687,6 +2689,9 @@ string_encode(PyStringObject *self, PyObject *args)
         return NULL;
     }
     return v;
+
+ onError:
+    return NULL;
 }
 
 
@@ -2710,6 +2715,8 @@ string_decode(PyStringObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, "|ss:decode", &encoding, &errors))
         return NULL;
     v = PyString_AsDecodedObject((PyObject *)self, encoding, errors);
+    if (v == NULL)
+        goto onError;
     if (!PyString_Check(v) && !PyUnicode_Check(v)) {
         PyErr_Format(PyExc_TypeError,
                      "decoder did not return a string/unicode object "
@@ -2719,6 +2726,9 @@ string_decode(PyStringObject *self, PyObject *args)
         return NULL;
     }
     return v;
+
+ onError:
+    return NULL;
 }
 
 
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 4550023a60d..2952c95fcf2 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -4935,6 +4935,8 @@ unicode_encode(PyUnicodeObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, "|ss:encode", &encoding, &errors))
         return NULL;
     v = PyUnicode_AsEncodedObject((PyObject *)self, encoding, errors);
+    if (v == NULL)
+        goto onError;
     if (!PyString_Check(v) && !PyUnicode_Check(v)) {
         PyErr_Format(PyExc_TypeError,
                      "encoder did not return a string/unicode object "
@@ -4944,6 +4946,9 @@ unicode_encode(PyUnicodeObject *self, PyObject *args)
         return NULL;
     }
     return v;
+
+ onError:
+    return NULL;
 }
 
 PyDoc_STRVAR(decode__doc__,
@@ -4966,6 +4971,8 @@ unicode_decode(PyStringObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, "|ss:decode", &encoding, &errors))
         return NULL;
     v = PyUnicode_AsDecodedObject((PyObject *)self, encoding, errors);
+    if (v == NULL)
+        goto onError;
     if (!PyString_Check(v) && !PyUnicode_Check(v)) {
         PyErr_Format(PyExc_TypeError,
                      "decoder did not return a string/unicode object "
@@ -4975,6 +4982,9 @@ unicode_decode(PyStringObject *self, PyObject *args)
         return NULL;
     }
     return v;
+
+ onError:
+    return NULL;
 }
 
 PyDoc_STRVAR(expandtabs__doc__,