diff --git a/Modules/_testinternalcapi/interpreter.c b/Modules/_testinternalcapi/interpreter.c
index 2cd23fa3c58849..653332f707326d 100644
--- a/Modules/_testinternalcapi/interpreter.c
+++ b/Modules/_testinternalcapi/interpreter.c
@@ -21,7 +21,7 @@ stop_tracing_and_jit(PyThreadState *tstate, _PyInterpreterFrame *frame)
 }
 #endif
 
-_PyJitEntryFuncPtr _Py_jit_entry;
+extern _PyJitEntryFuncPtr _Py_jit_entry;
 
 #if _Py_TAIL_CALL_INTERP
 #include "test_targets.h"