diff --git a/Modules/threadmodule.c b/Modules/threadmodule.c
index 036619a..2726045 100644
--- a/Modules/threadmodule.c
+++ b/Modules/threadmodule.c
@@ -294,7 +294,10 @@
 		}
 		
 	}
-	else if (self->dict != ldict) {
+
+	/* The call to tp_init above may have caused another thread to run.
+	   Install our ldict again. */
+	if (self->dict != ldict) {
 		Py_CLEAR(self->dict);
 		Py_INCREF(ldict);
 		self->dict = ldict;