diff --git a/book/07-git-tools/git-credential-read-only b/book/07-git-tools/git-credential-read-only
index ec8f4d1f4..b98833c4e 100755
--- a/book/07-git-tools/git-credential-read-only
+++ b/book/07-git-tools/git-credential-read-only
@@ -22,7 +22,7 @@ end
 
 File.readlines(path).each do |fileline| # <4>
     prot,user,pass,host = fileline.scan(/^(.*?):\/\/(.*?):(.*?)@(.*)$/).first
-    if prot == known['protocol'] and host == known['host'] then
+    if prot == known['protocol'] and host == known['host'] and user == known['username'] then
         puts "protocol=#{prot}"
         puts "host=#{host}"
         puts "username=#{user}"