1 files changed, 1 insertions, 1 deletions
diff --git a/t/lib/io_dup.t b/t/lib/io_dup.t
index c895fb4c25..0f17264dfa 100755
--- a/t/lib/io_dup.t
+++ b/t/lib/io_dup.t
@@ -3,7 +3,7 @@
 BEGIN {
     unless(grep /blib/, @INC) {
 	chdir 't' if -d 't';
-	unshift @INC, '../lib' if -d '../lib';
+	@INC = '../lib';
     }
 }