diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 5abde84ebc2efd..453be594d06203 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -1218,7 +1218,7 @@ typedef struct Tkapp_CallEvent {
     Tcl_Condition *done;
 } Tkapp_CallEvent;
 
-void
+static void
 Tkapp_CallDeallocArgs(Tcl_Obj** objv, Tcl_Obj** objStore, int objc)
 {
     int i;