diff --git a/Modules/_io/_iomodule.h b/Modules/_io/_iomodule.h
index afd638a120ba08..b97215d89138b4 100644
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@ -195,3 +195,11 @@ extern PyObject *_PyIOBase_cannot_pickle(PyObject *self, PyObject *args);
 #ifdef HAVE_WINDOWS_CONSOLE_IO
 extern char _PyIO_get_console_type(PyObject *);
 #endif
+
+
+typedef struct {
+    PyObject_HEAD
+
+    PyObject *dict;
+    PyObject *weakreflist;
+} iobase;
diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 7a0c516411c73b..b6dff7777a5b9a 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -2428,6 +2428,7 @@ static int
 bufferediobase_traverse(PyObject *self, visitproc visit, void *arg)
 {
     Py_VISIT(Py_TYPE(self));
+    Py_VISIT(((iobase *)self)->dict);
     return 0;
 }
 
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 14d48813aefe83..a489bc30e88535 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -26,12 +26,6 @@ class _io._RawIOBase "PyObject *" "clinic_state()->PyRawIOBase_Type"
  * IOBase class, an abstract class
  */
 
-typedef struct {
-    PyObject_HEAD
-
-    PyObject *dict;
-    PyObject *weakreflist;
-} iobase;
 
 PyDoc_STRVAR(iobase_doc,
     "The abstract base class for all I/O classes.\n"
@@ -1040,6 +1034,7 @@ static int
 rawiobase_traverse(PyObject *self, visitproc visit, void *arg)
 {
     Py_VISIT(Py_TYPE(self));
+    Py_VISIT(((iobase *)self)->dict);
     return 0;
 }
 
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index e858a1fb498f82..f736db1b232adb 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -171,6 +171,7 @@ static int
 textiobase_traverse(PyObject *self, visitproc visit, void *arg)
 {
     Py_VISIT(Py_TYPE(self));
+    Py_VISIT(((iobase *)self)->dict);
     return 0;
 }