diff --git a/newsfragments/2788.added.md b/newsfragments/2788.added.md
new file mode 100644
index 00000000000..2c744cef929
--- /dev/null
+++ b/newsfragments/2788.added.md
@@ -0,0 +1 @@
+Define `_PyErr_ChainExceptions()` FFI for CPython.
diff --git a/pyo3-ffi/src/cpython/pyerrors.rs b/pyo3-ffi/src/cpython/pyerrors.rs
index afc5ae93746..abbffc0b8c2 100644
--- a/pyo3-ffi/src/cpython/pyerrors.rs
+++ b/pyo3-ffi/src/cpython/pyerrors.rs
@@ -150,6 +150,11 @@ pub struct PyStopIterationObject {
     pub value: *mut PyObject,
 }
 
+extern "C" {
+    #[cfg(not(PyPy))]
+    pub fn _PyErr_ChainExceptions(typ: *mut PyObject, val: *mut PyObject, tb: *mut PyObject);
+}
+
 // skipped PyNameErrorObject
 // skipped PyAttributeErrorObject
 
@@ -160,8 +165,6 @@ pub struct PyStopIterationObject {
 // skipped _PyErr_GetTopmostException
 // skipped _PyErr_GetExcInfo
 
-// skipped _PyErr_ChainExceptions
-
 // skipped PyErr_SetFromErrnoWithUnicodeFilename
 
 // skipped _PyErr_FormatFromCause