diff --git a/src/if_py_both.h b/src/if_py_both.h
index 44b4baf..c7df93b 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -2250,6 +2250,9 @@
 {
     ListObject	*self;
 
+    if (list == NULL)
+	return NULL;
+
     self = (ListObject *) subtype->tp_alloc(subtype, 0);
     if (self == NULL)
 	return NULL;
@@ -2695,6 +2698,12 @@
     if (obj == NULL)
     {
 	li = list_find(l, (long) index);
+	if (li == NULL)
+	{
+	    PyErr_VIM_FORMAT(N_("internal error: failed to get Vim "
+			"list item %d"), (int) index);
+	    return -1;
+	}
 	vimlist_remove(l, li, li);
 	clear_tv(&li->li_tv);
 	vim_free(li);
@@ -2716,6 +2725,12 @@
     else
     {
 	li = list_find(l, (long) index);
+	if (li == NULL)
+	{
+	    PyErr_VIM_FORMAT(N_("internal error: failed to get Vim "
+			"list item %d"), (int) index);
+	    return -1;
+	}
 	clear_tv(&li->li_tv);
 	copy_tv(&tv, &li->li_tv);
 	clear_tv(&tv);
@@ -3897,7 +3912,7 @@
     PyObject_GC_UnTrack((void *)(self));
     if (self->win && self->win != INVALID_WINDOW_VALUE)
 	WIN_PYTHON_REF(self->win) = NULL;
-     Py_XDECREF(((PyObject *)(self->tabObject)));
+    Py_XDECREF(((PyObject *)(self->tabObject)));
     PyObject_GC_Del((void *)(self));
 }