diff --git a/lib/puma/client.rb b/lib/puma/client.rb
index a856a00d..ac2609a3 100644
--- a/lib/puma/client.rb
+++ b/lib/puma/client.rb
@@ -309,7 +309,7 @@ module Puma
       return @peerip if @peerip
 
       if @remote_addr_header
-        hdr = (@env[@remote_addr_header] || LOCALHOST_ADDR).split(/\s,/).first
+        hdr = (@env[@remote_addr_header] || LOCALHOST_ADDR).split(/[\s,]/).first
         @peerip = hdr
         return hdr
       end