diff --git a/lib/puma/client.rb b/lib/puma/client.rb
index 8dc20c14..a856a00d 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(" ").first
+        hdr = (@env[@remote_addr_header] || LOCALHOST_ADDR).split(/\s,/).first
         @peerip = hdr
         return hdr
       end
diff --git a/lib/puma/dsl.rb b/lib/puma/dsl.rb
index d69658be..ecf11f7e 100644
--- a/lib/puma/dsl.rb
+++ b/lib/puma/dsl.rb
@@ -311,7 +311,7 @@ module Puma
     # * header: http_header - set the remote address to the value of the
     #                          provided http header. For instance:
     #                          `set_remote_address header: "X-Real-IP"`.
-    #                          Only the first word (as separated by spaces)
+    #                          Only the first word (as separated by spaces or comma)
     #                          is used, allowing headers such as X-Forwarded-For
     #                          to be used as well.
     # * Any string - this allows you to hardcode remote address to any value