diff --git a/eval.c b/eval.c
index 5900f22dbd..f3a30dd159 100644
--- a/eval.c
+++ b/eval.c
@@ -531,7 +531,7 @@ setup_exception(rb_execution_context_t *ec, int tag, volatile VALUE mesg, VALUE
 		    mesg = rb_obj_dup(mesg);
 		}
 	    }
-	    if (cause != Qundef && !THROW_DATA_P(cause)) {
+            if (cause != Qundef && !THROW_DATA_P(cause)) {
 		exc_setup_cause(mesg, cause);
 	    }
 	    if (NIL_P(bt)) {