diff --git a/Objects/structseq.c b/Objects/structseq.c
index bf59f47..73795b6 100644
--- a/Objects/structseq.c
+++ b/Objects/structseq.c
@@ -11,6 +11,7 @@
 #include "pycore_tuple.h"         // _PyTuple_FromArray()
 #include "pycore_object.h"        // _PyObject_GC_TRACK()
 #include "structmember.h"         // PyMemberDef
+#include "pycore_structseq.h"     // PyStructSequence_InitType()
 
 static const char visible_length_key[] = "n_sequence_fields";
 static const char real_length_key[] = "n_fields";