diff --git a/lib/puma/minissl.rb b/lib/puma/minissl.rb
index 9ee35ef0..a65c1c64 100644
--- a/lib/puma/minissl.rb
+++ b/lib/puma/minissl.rb
@@ -249,7 +249,7 @@ module Puma
       end
 
       def close
-        @socket.close
+        @socket.close unless @socket.closed?       # closed? call is for Windows
       end
     end
   end