diff --git a/Python/ast.c b/Python/ast.c
index c58b4a6..8ac2e60 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -551,7 +551,7 @@ validate_exprs(asdl_expr_seq *exprs, expr_context_ty ctx, int null_ok)
 }
 
 int
-PyAST_Validate(mod_ty mod)
+_PyAST_Validate(mod_ty mod)
 {
     int res = 0;
 
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 52591c4..4683103 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -4,6 +4,7 @@
 #include <ctype.h>
 #include "ast.h"
 #undef Yield   /* undefine macro conflicting with <winbase.h> */
+#include "pycore_ast.h"           // _PyAST_Validate()
 #include "pycore_object.h"        // _Py_AddToAllObjects()
 #include "pycore_pyerrors.h"      // _PyErr_NoMemory()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
@@ -835,7 +836,7 @@ builtin_compile_impl(PyObject *module, PyObject *source, PyObject *filename,
                 PyArena_Free(arena);
                 goto error;
             }
-            if (!PyAST_Validate(mod)) {
+            if (!_PyAST_Validate(mod)) {
                 PyArena_Free(arena);
                 goto error;
             }