diff --git a/dns-client.rb b/dns-client.rb
index 11a4503..abe0012 100644
--- a/dns-client.rb
+++ b/dns-client.rb
@@ -220,9 +220,9 @@ end
 
 def host_sshfp(keys)
   keys.flat_map { |keyfile|
-    `ssh-keygen -r hostname #{keyfile}`.split("\n")
+    `ssh-keygen -r hostname -f #{keyfile}`.split("\n")
   }.map { |fp|
-    fp..match(/[0-9] [0-9] [a-fA-F0-9]{32,64}$/)[0]
+    fp.match(/[0-9] [0-9] [a-fA-F0-9]{32,64}$/)[0]
   }.compact
 end