diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index 8629ab7..2e47a1c 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -974,13 +974,17 @@
     Py_buffer self_bytes, other_bytes;
     PyObject *res;
     Py_ssize_t minsize;
-    int cmp;
+    int cmp, rc;
 
     /* Bytes can be compared to anything that supports the (binary)
        buffer API.  Except that a comparison with Unicode is always an
        error, even if the comparison is for equality. */
-    if (PyObject_IsInstance(self, (PyObject*)&PyUnicode_Type) ||
-        PyObject_IsInstance(other, (PyObject*)&PyUnicode_Type)) {
+    rc = PyObject_IsInstance(self, (PyObject*)&PyUnicode_Type);
+    if (!rc)
+        rc = PyObject_IsInstance(other, (PyObject*)&PyUnicode_Type);
+    if (rc < 0)
+        return NULL;
+    if (rc) {
         if (Py_BytesWarningFlag && (op == Py_EQ || op == Py_NE)) {
             if (PyErr_WarnEx(PyExc_BytesWarning,
                             "Comparison between bytearray and string", 1))
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index b9b49ac..5768154 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -816,17 +816,23 @@
     Py_ssize_t len_a, len_b;
     Py_ssize_t min_len;
     PyObject *result;
+    int rc;
 
     /* Make sure both arguments are strings. */
     if (!(PyBytes_Check(a) && PyBytes_Check(b))) {
-        if (Py_BytesWarningFlag && (op == Py_EQ || op == Py_NE) &&
-            (PyObject_IsInstance((PyObject*)a,
-                                 (PyObject*)&PyUnicode_Type) ||
-            PyObject_IsInstance((PyObject*)b,
-                                 (PyObject*)&PyUnicode_Type))) {
-            if (PyErr_WarnEx(PyExc_BytesWarning,
-                        "Comparison between bytes and string", 1))
+        if (Py_BytesWarningFlag && (op == Py_EQ || op == Py_NE)) {
+            rc = PyObject_IsInstance((PyObject*)a,
+                                     (PyObject*)&PyUnicode_Type);
+            if (!rc)
+                rc = PyObject_IsInstance((PyObject*)b,
+                                         (PyObject*)&PyUnicode_Type);
+            if (rc < 0)
                 return NULL;
+            if (rc) {
+                if (PyErr_WarnEx(PyExc_BytesWarning,
+                                 "Comparison between bytes and string", 1))
+                    return NULL;
+            }
         }
         result = Py_NotImplemented;
     }
diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c
index ca66a45..c4ba715 100644
--- a/Objects/rangeobject.c
+++ b/Objects/rangeobject.c
@@ -194,8 +194,11 @@
     }
 
     /* if (lo >= hi), return length of 0. */
-    if (PyObject_RichCompareBool(lo, hi, Py_GE) == 1) {
+    cmp_result = PyObject_RichCompareBool(lo, hi, Py_GE);
+    if (cmp_result != 0) {
         Py_XDECREF(step);
+        if (cmp_result < 0)
+            return NULL;
         return PyLong_FromLong(0);
     }
 
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 34e43b9..304519c 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -1569,9 +1569,15 @@
     if (PyDict_CheckExact(other)) {
         while (set_next(so, &pos, &entry)) {
             setentry entrycopy;
+            int rv;
             entrycopy.hash = entry->hash;
             entrycopy.key = entry->key;
-            if (!_PyDict_Contains(other, entry->key, entry->hash)) {
+            rv = _PyDict_Contains(other, entry->key, entry->hash);
+            if (rv < 0) {
+                Py_DECREF(result);
+                return NULL;
+            }
+            if (!rv) {
                 if (set_add_entry((PySetObject *)result, &entrycopy) == -1) {
                     Py_DECREF(result);
                     return NULL;
@@ -1807,7 +1813,8 @@
 static PyObject *
 set_richcompare(PySetObject *v, PyObject *w, int op)
 {
-    PyObject *r1, *r2;
+    PyObject *r1;
+    int r2;
 
     if(!PyAnySet_Check(w))
         Py_RETURN_NOTIMPLEMENTED;
@@ -1825,9 +1832,11 @@
         r1 = set_richcompare(v, w, Py_EQ);
         if (r1 == NULL)
             return NULL;
-        r2 = PyBool_FromLong(PyObject_Not(r1));
+        r2 = PyObject_IsTrue(r1);
         Py_DECREF(r1);
-        return r2;
+        if (r2 < 0)
+            return NULL;
+        return PyBool_FromLong(!r2);
     case Py_LE:
         return set_issubset(v, w);
     case Py_GE: