Index: Modules/_tkinter.c
===================================================================
--- Modules/_tkinter.c	(revision 66489)
+++ Modules/_tkinter.c	(working copy)
@@ -610,6 +610,13 @@
 	}
 #endif
 #ifdef WITH_THREAD
+    if (!(v->threaded)) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "Tcl/Tk was not compiled with --enable-threads but "
+                        "Python has threads enabled");
+        Py_DECREF(v);
+        return 0;
+    }
 	if (v->threaded && tcl_lock) {
 	    /* If Tcl is threaded, we don't need the lock. */
 	    PyThread_free_lock(tcl_lock);