diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 # Changelog for vega-view
 
+## 0.4.0.2
+
+Bump dependency for scotty to support version 0.30 and drop anything
+below 0.21.
+
 ## 0.4.0.1
 
 Bump dependencies for aeson, bytestring, filepath, scotty, and
diff --git a/app/Main.hs b/app/Main.hs
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -65,7 +65,7 @@
 import Web.Scotty (ScottyM, ActionM
                   , get, html, json
                   , notFound
-                  , param  -- deprecated in Scotty 0.20
+                  , pathParam
                   , redirect, regex
                   , status, scotty
                   , text)
@@ -974,11 +974,11 @@
   get "/display/" (dirPage ".")
 
   get (regex "^/display/(.+)$") $ do
-    infile <- param "1"
+    infile <- pathParam "1"
     displayPage infile
 
   get (regex "^/embed/(.+)$") $ do
-    infile <- param "1"
+    infile <- pathParam "1"
     embedPage infile
 
   notFound errorStatus
diff --git a/vega-view.cabal b/vega-view.cabal
--- a/vega-view.cabal
+++ b/vega-view.cabal
@@ -1,5 +1,5 @@
 name:           vega-view
-version:        0.4.0.1
+version:        0.4.0.2
 synopsis:       Easily view Vega or Vega-Lite visualizations.
 description:    A web server that is used to view all the Vega and Vega-Lite
                 specifications in a directory, or sub-directory. It is similar
@@ -12,7 +12,7 @@
 bug-reports:    https://github.com/DougBurke/vega-view/issues
 author:         Douglas Burke
 maintainer:     dburke.gw@gmail.com
-copyright:      2019, 2020, 2021, 2024 Douglas Burke
+copyright:      2019, 2020, 2021, 2024, 2026 Douglas Burke
 license:        BSD3
 license-file:   LICENSE
 build-type:     Simple
@@ -43,7 +43,7 @@
               , directory >= 1.2.5.0 && < 1.4
               , filepath >= 1.4 && < 1.6
               , http-types >= 0.9 && < 0.13
-              , scotty >= 0.11 && < 0.23
+              , scotty >= 0.21 && < 0.40
               , text >= 1.2 && < 2.2
               , unordered-containers >= 0.2 && < 0.3