diff --git a/R/chrome.R b/R/chrome.R
index 9fdbaed3..122bd5a2 100644
--- a/R/chrome.R
+++ b/R/chrome.R
@@ -50,7 +50,7 @@ chrome_print = function(
     )
     sv = servr::httd(
       dirname(url), daemon = TRUE, browser = FALSE, verbose = FALSE,
-      initpath = httpuv::encodeURIComponent(basename(url))
+      port = random_port(), initpath = httpuv::encodeURIComponent(basename(url))
     )
     on.exit(sv$stop_server(), add = TRUE)
     url = sv$url
@@ -74,7 +74,7 @@ chrome_print = function(
     '--headless', '--no-first-run', '--no-default-browser-check'
   ))
 
-  debug_port = servr::random_port()
+  debug_port = random_port()
   ps = processx::process$new(browser, c(
     paste0('--remote-debugging-port=', debug_port),
     paste0('--user-data-dir=', work_dir), extra_args
diff --git a/R/utils.R b/R/utils.R
index cd07d5fe..b1afcae6 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -27,3 +27,7 @@ merge_list = function(x, y) {
   x[names(y)] = y
   x
 }
+
+# don't prefer the port 4321 (otherwise we may see the meaningless error message
+# "createTcpServer: address already in use" too often)
+random_port = function() servr::random_port(NULL)