diff --git a/Objects/accu.c b/Objects/accu.c
index 88e8f08..5bd2ee4 100644
--- a/Objects/accu.c
+++ b/Objects/accu.c
@@ -1,6 +1,7 @@
 /* Accumulator struct implementation */
 
 #include "Python.h"
+#include "accu.h"
 
 static PyObject *
 join_list_unicode(PyObject *lst)
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 00de597..b9ef0d0 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -1,6 +1,7 @@
 /* List object implementation */
 
 #include "Python.h"
+#include "accu.h"
 
 #ifdef STDC_HEADERS
 #include <stddef.h>
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index f6dbc31..e99eda0 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -2,6 +2,7 @@
 /* Tuple object implementation */
 
 #include "Python.h"
+#include "accu.h"
 
 /* Speed optimization to avoid frequent malloc/free of small tuples */
 #ifndef PyTuple_MAXSAVESIZE