diff --git a/Include/pylifecycle.h b/Include/pylifecycle.h
index 1df114a73d..6f49e77c56 100644
--- a/Include/pylifecycle.h
+++ b/Include/pylifecycle.h
@@ -16,6 +16,8 @@ PyAPI_FUNC(void) Py_Finalize(void);
 PyAPI_FUNC(int) Py_FinalizeEx(void);
 #endif
 PyAPI_FUNC(int) Py_IsInitialized(void);
+/* runtime_initialized */
+PyAPI_FUNC(int) _Py_IsInitialized(void);
 
 /* Subinterpreter support */
 PyAPI_FUNC(PyThreadState *) Py_NewInterpreter(void);
diff --git a/Python/ceval_gil.h b/Python/ceval_gil.h
index 34d48c990c..2073757247 100644
--- a/Python/ceval_gil.h
+++ b/Python/ceval_gil.h
@@ -186,6 +186,7 @@ take_gil(struct _ceval_runtime_state *ceval, PyThreadState *tstate)
     if (tstate == NULL) {
         Py_FatalError("take_gil: NULL tstate");
     }
+    assert(_Py_IsInitialized());
 
     struct _gil_runtime_state *gil = &ceval->gil;
     int err = errno;
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index d29b293b79..61a0024f30 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -95,6 +95,12 @@ _PyRuntime_Finalize(void)
     runtime_initialized = 0;
 }
 
+int
+_Py_IsInitialized(void)
+{
+    return runtime_initialized != 0;
+}
+
 int
 _Py_IsFinalizing(void)
 {