diff -r 0cb037bb0f9a Objects/bytearrayobject.c
--- a/Objects/bytearrayobject.c	Mon May 25 21:24:00 2015 -0500
+++ b/Objects/bytearrayobject.c	Tue Jun 23 10:04:59 2015 +0200
@@ -2305,8 +2305,8 @@
         return NULL;
     }
     if (where < 0)
-        where += Py_SIZE(self);
-    if (where < 0 || where >= Py_SIZE(self)) {
+        where += n;
+    if (where < 0 || where >= n) {
         PyErr_SetString(PyExc_IndexError, "pop index out of range");
         return NULL;
     }
@@ -2314,7 +2314,7 @@
         return NULL;
 
     value = self->ob_bytes[where];
-    memmove(self->ob_bytes + where, self->ob_bytes + where + 1, n - where);
+    memmove(self->ob_bytes + where, self->ob_bytes + where + 1, n - where - 1);
     if (PyByteArray_Resize((PyObject *)self, n - 1) < 0)
         return NULL;
 
@@ -2345,7 +2345,7 @@
     if (!_canresize(self))
         return NULL;
 
-    memmove(self->ob_bytes + where, self->ob_bytes + where + 1, n - where);
+    memmove(self->ob_bytes + where, self->ob_bytes + where + 1, n - where - 1);
     if (PyByteArray_Resize((PyObject *)self, n - 1) < 0)
         return NULL;