diff --git a/Include/Python.h b/Include/Python.h
index cb24c8d33ee6f2..ac516e880ddb96 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -146,4 +146,10 @@
 #include "pyfpe.h"
 #include "tracemalloc.h"
 
+#if defined(Py_BUILD_CORE) || defined(Py_BUILD_CORE_BUILTIN)
+   /* bpo-35081: Automatically include pycore_object.h in Python.h, to avoid
+      to have to add an explicit #include "pycore_object.h" to each C file. */
+#  include "pycore_object.h"
+#endif
+
 #endif /* !Py_PYTHON_H */
diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
new file mode 100644
index 00000000000000..5c180a516bdac7
--- /dev/null
+++ b/Include/internal/pycore_object.h
@@ -0,0 +1,91 @@
+#ifndef Py_INTERNAL_OBECT_H
+#define Py_INTERNAL_OBECT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if !defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_BUILTIN)
+#  error "this header requires Py_BUILD_CORE or Py_BUILD_CORE_BUILTIN defined"
+#endif
+
+#include "pycore_pystate.h"   /* _PyRuntime */
+
+/* Bit flags for _gc_prev */
+/* Bit 0 is set when tp_finalize is called */
+#define _PyGC_PREV_MASK_FINALIZED  (1)
+/* Bit 1 is set when the object is in generation which is GCed currently. */
+#define _PyGC_PREV_MASK_COLLECTING (2)
+/* The (N-2) most significant bits contain the real address. */
+#define _PyGC_PREV_SHIFT           (2)
+#define _PyGC_PREV_MASK            (((uintptr_t) -1) << _PyGC_PREV_SHIFT)
+
+
+// Lowest bit of _gc_next is used for flags only in GC.
+// But it is always 0 for normal code.
+#define _PyGCHead_NEXT(g)        ((PyGC_Head*)(g)->_gc_next)
+#define _PyGCHead_SET_NEXT(g, p) ((g)->_gc_next = (uintptr_t)(p))
+
+// Lowest two bits of _gc_prev is used for _PyGC_PREV_MASK_* flags.
+#define _PyGCHead_PREV(g) ((PyGC_Head*)((g)->_gc_prev & _PyGC_PREV_MASK))
+#define _PyGCHead_SET_PREV(g, p) do { \
+    assert(((uintptr_t)p & ~_PyGC_PREV_MASK) == 0); \
+    (g)->_gc_prev = ((g)->_gc_prev & ~_PyGC_PREV_MASK) \
+        | ((uintptr_t)(p)); \
+    } while (0)
+
+
+#define _PyGCHead_FINALIZED(g) \
+    (((g)->_gc_prev & _PyGC_PREV_MASK_FINALIZED) != 0)
+#define _PyGCHead_SET_FINALIZED(g) \
+    ((g)->_gc_prev |= _PyGC_PREV_MASK_FINALIZED)
+
+#define _PyGC_FINALIZED(o) \
+    _PyGCHead_FINALIZED(_Py_AS_GC(o))
+#define _PyGC_SET_FINALIZED(o) \
+    _PyGCHead_SET_FINALIZED(_Py_AS_GC(o))
+
+
+/* Tell the GC to track this object.
+ *
+ * NB: While the object is tracked by the collector, it must be safe to call the
+ * ob_traverse method.
+ *
+ * Internal note: _PyRuntime.gc.generation0->_gc_prev doesn't have any bit flags
+ * because it's not object header.  So we don't use _PyGCHead_PREV() and
+ * _PyGCHead_SET_PREV() for it to avoid unnecessary bitwise operations.
+ */
+#define _PyObject_GC_TRACK(o) do { \
+    PyGC_Head *g = _Py_AS_GC(o); \
+    if (g->_gc_next != 0) { \
+        Py_FatalError("GC object already tracked"); \
+    } \
+    assert((g->_gc_prev & _PyGC_PREV_MASK_COLLECTING) == 0); \
+    PyGC_Head *last = (PyGC_Head*)(_PyRuntime.gc.generation0->_gc_prev); \
+    _PyGCHead_SET_NEXT(last, g); \
+    _PyGCHead_SET_PREV(g, last); \
+    _PyGCHead_SET_NEXT(g, _PyRuntime.gc.generation0); \
+    _PyRuntime.gc.generation0->_gc_prev = (uintptr_t)g; \
+    } while (0);
+
+
+/* Tell the GC to stop tracking this object.
+ *
+ * Internal note: This may be called while GC.  So _PyGC_PREV_MASK_COLLECTING must
+ * be cleared.  But _PyGC_PREV_MASK_FINALIZED bit is kept.
+ */
+#define _PyObject_GC_UNTRACK(o) do { \
+    PyGC_Head *g = _Py_AS_GC(o); \
+    PyGC_Head *prev = _PyGCHead_PREV(g); \
+    PyGC_Head *next = _PyGCHead_NEXT(g); \
+    assert(next != NULL); \
+    _PyGCHead_SET_NEXT(prev, next); \
+    _PyGCHead_SET_PREV(next, prev); \
+    g->_gc_next = 0; \
+    g->_gc_prev &= _PyGC_PREV_MASK_FINALIZED; \
+    } while (0);
+
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_INTERNAL_OBECT_H */
diff --git a/Include/objimpl.h b/Include/objimpl.h
index e1946c74560cff..97c0f30a093b4f 100644
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -290,84 +290,6 @@ typedef struct {
         (!PyTuple_CheckExact(obj) || _PyObject_GC_IS_TRACKED(obj)))
 #endif
 
-
-#if defined(Py_BUILD_CORE) || defined(Py_BUILD_CORE_BUILTIN)
-
-/* Bit flags for _gc_prev */
-/* Bit 0 is set when tp_finalize is called */
-#define _PyGC_PREV_MASK_FINALIZED  (1)
-/* Bit 1 is set when the object is in generation which is GCed currently. */
-#define _PyGC_PREV_MASK_COLLECTING (2)
-/* The (N-2) most significant bits contain the real address. */
-#define _PyGC_PREV_SHIFT           (2)
-#define _PyGC_PREV_MASK            (((uintptr_t) -1) << _PyGC_PREV_SHIFT)
-
-// Lowest bit of _gc_next is used for flags only in GC.
-// But it is always 0 for normal code.
-#define _PyGCHead_NEXT(g)        ((PyGC_Head*)(g)->_gc_next)
-#define _PyGCHead_SET_NEXT(g, p) ((g)->_gc_next = (uintptr_t)(p))
-
-// Lowest two bits of _gc_prev is used for _PyGC_PREV_MASK_* flags.
-#define _PyGCHead_PREV(g) ((PyGC_Head*)((g)->_gc_prev & _PyGC_PREV_MASK))
-#define _PyGCHead_SET_PREV(g, p) do { \
-    assert(((uintptr_t)p & ~_PyGC_PREV_MASK) == 0); \
-    (g)->_gc_prev = ((g)->_gc_prev & ~_PyGC_PREV_MASK) \
-        | ((uintptr_t)(p)); \
-    } while (0)
-
-#define _PyGCHead_FINALIZED(g) \
-    (((g)->_gc_prev & _PyGC_PREV_MASK_FINALIZED) != 0)
-#define _PyGCHead_SET_FINALIZED(g) \
-    ((g)->_gc_prev |= _PyGC_PREV_MASK_FINALIZED)
-
-#define _PyGC_FINALIZED(o) \
-    _PyGCHead_FINALIZED(_Py_AS_GC(o))
-#define _PyGC_SET_FINALIZED(o) \
-    _PyGCHead_SET_FINALIZED(_Py_AS_GC(o))
-
-/* Tell the GC to track this object.
- *
- * NB: While the object is tracked by the collector, it must be safe to call the
- * ob_traverse method.
- *
- * Internal note: _PyRuntime.gc.generation0->_gc_prev doesn't have any bit flags
- * because it's not object header.  So we don't use _PyGCHead_PREV() and
- * _PyGCHead_SET_PREV() for it to avoid unnecessary bitwise operations.
- *
- * The PyObject_GC_Track() function is the public version of this macro.
- */
-#define _PyObject_GC_TRACK(o) do { \
-    PyGC_Head *g = _Py_AS_GC(o); \
-    if (g->_gc_next != 0) { \
-        Py_FatalError("GC object already tracked"); \
-    } \
-    assert((g->_gc_prev & _PyGC_PREV_MASK_COLLECTING) == 0); \
-    PyGC_Head *last = (PyGC_Head*)(_PyRuntime.gc.generation0->_gc_prev); \
-    _PyGCHead_SET_NEXT(last, g); \
-    _PyGCHead_SET_PREV(g, last); \
-    _PyGCHead_SET_NEXT(g, _PyRuntime.gc.generation0); \
-    _PyRuntime.gc.generation0->_gc_prev = (uintptr_t)g; \
-    } while (0);
-
-/* Tell the GC to stop tracking this object.
- *
- * Internal note: This may be called while GC.  So _PyGC_PREV_MASK_COLLECTING must
- * be cleared.  But _PyGC_PREV_MASK_FINALIZED bit is kept.
- *
- * The PyObject_GC_UnTrack() function is the public version of this macro.
- */
-#define _PyObject_GC_UNTRACK(o) do { \
-    PyGC_Head *g = _Py_AS_GC(o); \
-    PyGC_Head *prev = _PyGCHead_PREV(g); \
-    PyGC_Head *next = _PyGCHead_NEXT(g); \
-    assert(next != NULL); \
-    _PyGCHead_SET_NEXT(prev, next); \
-    _PyGCHead_SET_PREV(next, prev); \
-    g->_gc_next = 0; \
-    g->_gc_prev &= _PyGC_PREV_MASK_FINALIZED; \
-    } while (0);
-#endif   /* defined(Py_BUILD_CORE) || defined(Py_BUILD_CORE_BUILTIN) */
-
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) _PyObject_GC_Malloc(size_t size);
 PyAPI_FUNC(PyObject *) _PyObject_GC_Calloc(size_t size);