diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+## 0.4.2 [2023.10.05]
+* Support building with `scotty-0.20`.
+
 ## 0.4.1 [2021.10.09]
 * Allow building with `aeson-2.0.0.0`.
 
diff --git a/Web/Scotty/Comet.hs b/Web/Scotty/Comet.hs
--- a/Web/Scotty/Comet.hs
+++ b/Web/Scotty/Comet.hs
@@ -16,7 +16,8 @@
     , defaultOptions
     ) where
 
-import Web.Scotty (ScottyM, text, post, capture, param, setHeader, get, ActionM, jsonData)
+import qualified Web.Scotty as Scotty
+import Web.Scotty (ScottyM, text, post, capture, setHeader, get, ActionM, jsonData)
 import Data.Aeson (Value(..))
 import Control.Monad
 import Control.Concurrent.STM as STM
@@ -104,7 +105,7 @@
        get (capture $ prefix opt ++ "/act/" ++ server_id ++ "/:id/:act") $ do
                 setHeader "Cache-Control" "max-age=0, no-cache, private, no-store, must-revalidate"
                 -- do something and return a new list of commands to the client
-                num <- param "id"
+                num <- captureParam "id"
 
                 when (verbose opt >= 2) $ liftIO $ putStrLn $
                     "Kansas Comet: get .../act/" ++ show num
@@ -141,8 +142,8 @@
 
        post (capture $ prefix opt ++ "/reply/" ++ server_id ++ "/:id/:uq") $ do
                setHeader "Cache-Control" "max-age=0, no-cache, private, no-store, must-revalidate"
-               num <- param "id"
-               uq :: Int <- param "uq"
+               num <- captureParam "id"
+               uq :: Int <- captureParam "uq"
                --liftIO $ print (num :: Int, event :: String)
 
                when (verbose opt >= 2) $ liftIO $ putStrLn $
@@ -171,7 +172,7 @@
 
        post (capture $ prefix opt ++ "/event/" ++ server_id ++ "/:id") $ do
                setHeader "Cache-Control" "max-age=0, no-cache, private, no-store, must-revalidate"
-               num <- param "id"
+               num <- captureParam "id"
 
                when (verbose opt >= 2) $ liftIO $ putStrLn $
                     "Kansas Comet: post .../event/" ++ show num
@@ -200,6 +201,12 @@
     lookupKM = KeyMap.lookup
 #else
     lookupKM = HashMap.lookup
+#endif
+
+#if MIN_VERSION_scotty(0,20,0)
+    captureParam = Scotty.captureParam
+#else
+    captureParam = Scotty.param
 #endif
 
 -- | 'kCometPlugin' provides the location of the Kansas Comet jQuery plugin.
diff --git a/kansas-comet.cabal b/kansas-comet.cabal
--- a/kansas-comet.cabal
+++ b/kansas-comet.cabal
@@ -1,5 +1,5 @@
 Name:                kansas-comet
-Version:             0.4.1
+Version:             0.4.2
 Synopsis:            A JavaScript push mechanism based on the comet idiom
 Homepage:            https://github.com/ku-fpg/kansas-comet/
 Bug-reports:         https://github.com/ku-fpg/kansas-comet/issues
@@ -21,8 +21,11 @@
                    , GHC == 8.4.4
                    , GHC == 8.6.5
                    , GHC == 8.8.4
-                   , GHC == 8.10.4
-                   , GHC == 9.0.1
+                   , GHC == 8.10.7
+                   , GHC == 9.0.2
+                   , GHC == 9.2.7
+                   , GHC == 9.4.4
+                   , GHC == 9.6.1
 Description:
   A transport-level remote JavaScript RESTful push mechanism.
 
@@ -37,15 +40,18 @@
                        -- TODO: Eventually, we should bump the lower version
                        -- bounds to >=2 so that we can remove some CPP in
                        -- Web.Scotty.Comet.
-                       aeson                >= 0.9      && < 2.1,
-                       base                 >= 4.6      && < 4.16,
-                       containers           >= 0.4      && < 0.7,
+                       aeson                >= 0.9      && < 2.3,
+                       base                 >= 4.6      && < 4.20,
+                       containers           >= 0.4      && < 0.8,
                        data-default-class   >= 0.0.1    && < 0.2,
-                       scotty               >= 0.10     && < 0.13,
+                       -- TODO: Eventually, we should bump the lower version
+                       -- bounds to >=0.20 so that we can remove some CPP in
+                       -- Web.Scotty.Comet.
+                       scotty               >= 0.10     && < 0.21,
                        stm                  >= 2.2      && < 2.6,
-                       text                 >= 0.11.3.1 && < 1.6,
-                       time                 >= 1.2      && < 1.11,
-                       transformers         >= 0.3      && < 0.6,
+                       text                 >= 0.11.3.1 && < 2.2,
+                       time                 >= 1.2      && < 1.13,
+                       transformers         >= 0.3      && < 0.7,
                        unordered-containers >= 0.2.3    && < 0.3
 
   GHC-options: -Wall