diff --git a/test/net/http/test_httpresponse.rb b/test/net/http/test_httpresponse.rb
index 13e26727..e902b4f3 100644
--- a/test/net/http/test_httpresponse.rb
+++ b/test/net/http/test_httpresponse.rb
@@ -97,7 +97,7 @@ def test_multiline_header_whitespace_only
     io = dummy_io(<<EOS)
 HTTP/1.1 200 OK
 Content-Length: 5
- 	
+#{" \t"}
 X-After: value
 
 hello
@@ -116,7 +116,7 @@ def test_multiline_header_whitespace_only
   def test_multiline_header_no_preceding_header
     io = dummy_io(<<EOS)
 HTTP/1.1 200 OK
- 	
+#{" \t"}
 Content-Length: 5
 
 hello