diff --git a/Python/_warnings.c b/Python/_warnings.c
index e4dfb73..d005f12 100644
--- a/Python/_warnings.c
+++ b/Python/_warnings.c
@@ -1,5 +1,6 @@
 #include "Python.h"
 #include "pycore_initconfig.h"
+#include "pycore_interp.h"        // PyInterpreterState.warnings
 #include "pycore_pyerrors.h"
 #include "pycore_pystate.h"
 #include "frameobject.h"
diff --git a/Python/codecs.c b/Python/codecs.c
index 7b35ded..6691985 100644
--- a/Python/codecs.c
+++ b/Python/codecs.c
@@ -9,6 +9,7 @@
    ------------------------------------------------------------------------ */
 
 #include "Python.h"
+#include "pycore_interp.h"     // PyInterpreterState.codec_search_path
 #include "pycore_pystate.h"
 #include "ucnhash.h"
 #include <ctype.h>
diff --git a/Python/dynload_shlib.c b/Python/dynload_shlib.c
index 3603871..223e0d0 100644
--- a/Python/dynload_shlib.c
+++ b/Python/dynload_shlib.c
@@ -2,6 +2,7 @@
 /* Support for dynamic loading of extension modules */
 
 #include "Python.h"
+#include "pycore_interp.h"    // _PyInterpreterState.dlopenflags
 #include "pycore_pystate.h"   // _PyInterpreterState_GET_UNSAFE()
 #include "importdl.h"
 
diff --git a/Python/import.c b/Python/import.c
index d79fa18..3bf8fe0 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -9,6 +9,7 @@
 #include "pycore_pyhash.h"
 #include "pycore_pylifecycle.h"
 #include "pycore_pymem.h"
+#include "pycore_interp.h"       // _PyInterpreterState_ClearModules()
 #include "pycore_pystate.h"
 #include "pycore_sysmodule.h"
 #include "errcode.h"
diff --git a/Python/initconfig.c b/Python/initconfig.c
index e63d6f6..43e0ccb 100644
--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -3,6 +3,7 @@
 #include "pycore_fileutils.h"
 #include "pycore_getopt.h"
 #include "pycore_initconfig.h"
+#include "pycore_interp.h"    // _PyInterpreterState.runtime
 #include "pycore_pathconfig.h"
 #include "pycore_pyerrors.h"
 #include "pycore_pylifecycle.h"
diff --git a/Python/preconfig.c b/Python/preconfig.c
index 89a6227..db32875 100644
--- a/Python/preconfig.c
+++ b/Python/preconfig.c
@@ -1,8 +1,9 @@
 #include "Python.h"
-#include "pycore_initconfig.h"
 #include "pycore_getopt.h"
-#include "pycore_pystate.h"   /* _PyRuntime_Initialize() */
-#include <locale.h>       /* setlocale() */
+#include "pycore_initconfig.h"
+#include "pycore_pymem.h"      // _PyMem_GetAllocatorName()
+#include "pycore_pystate.h"    // _PyRuntime_Initialize()
+#include <locale.h>            // setlocale()
 
 
 #define DECODE_LOCALE_ERR(NAME, LEN) \
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index fd0a9c0..814e4ab 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -17,7 +17,9 @@
 #include "Python.h"
 #include "code.h"
 #include "frameobject.h"
-#include "pycore_ceval.h"
+#include "pycore_ceval.h"        // _Py_RecursionLimitLowerWaterMark()
+#include "pycore_pystate.h"      // _PyThreadState_GET()
+#include "pycore_tupleobject.h"
 #include "pycore_initconfig.h"
 #include "pycore_pathconfig.h"
 #include "pycore_pyerrors.h"
diff --git a/Python/thread_nt.h b/Python/thread_nt.h
index 23d585c..e4bd0f7 100644
--- a/Python/thread_nt.h
+++ b/Python/thread_nt.h
@@ -1,3 +1,4 @@
+#include "pycore_interp.h"    // _PyInterpreterState.pythread_stacksize
 
 /* This code implemented by Dag.Gruneau@elsa.preseco.comm.se */
 /* Fast NonRecursiveMutex support by Yakov Markovitch, markovitch@iso.ru */
diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h
index e3497e7..440d845 100644
--- a/Python/thread_pthread.h
+++ b/Python/thread_pthread.h
@@ -1,3 +1,4 @@
+#include "pycore_interp.h"    // _PyInterpreterState.pythread_stacksize
 
 /* Posix threads interface */