diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Revision history for hpc-codecov
 
+## 0.6.4.1 -- 2026-05-15
+
+- Modify internal test to support ``tasty`` 1.5.4.
+
 ## 0.6.4.0 -- 2026-02-13
 
 - Modify the version range of ``time`` and ``containers`` packages to
diff --git a/hpc-codecov.cabal b/hpc-codecov.cabal
--- a/hpc-codecov.cabal
+++ b/hpc-codecov.cabal
@@ -1,6 +1,6 @@
 cabal-version:       2.0
 name:                hpc-codecov
-version:             0.6.4.0
+version:             0.6.4.1
 synopsis:            Generate reports from hpc data
 license:             BSD3
 license-file:        LICENSE
@@ -88,7 +88,7 @@
                      , array       >= 0.5   && < 0.6
                      , bytestring  >= 0.10  && < 0.13
                      , containers  >= 0.6   && < 0.9
-                     , directory   >= 1.3.0 && < 1.4.0
+                     , directory   >= 1.3.0 && < 1.4
                      , filepath    >= 1.4.1 && < 1.6
                      , hpc         >= 0.6   && < 0.8
                      , time        >= 1.9   && < 1.16
diff --git a/test/Test/Main.hs b/test/Test/Main.hs
--- a/test/Test/Main.hs
+++ b/test/Test/Main.hs
@@ -46,6 +46,11 @@
 import           Test.Tasty                  (DependencyType (..),
                                               TestTree, after, defaultMain,
                                               testGroup, withResource)
+
+#if MIN_VERSION_tasty(1,5,4)
+import           Test.Tasty                  (dependentTestGroup)
+#endif
+
 import           Test.Tasty.HUnit            (assertEqual, assertFailure,
                                               testCase)
 
@@ -79,7 +84,7 @@
     , "================================="
     , "" ]
 
-  defaultMain $ testGroup "main" $
+  defaultMain $ orderedTestGroup "main" $
     [reportTest, cmdline, recipReport, exceptionTest, parserTest] ++
     [exprOnly, ignoreDittos] ++
     [selfReportTest | not test_in_test, isJust mb_tool] ++
@@ -87,8 +92,8 @@
     [discoverCabalTest | not test_in_test, mb_tool == Just Cabal]
 
 parserTest :: TestTree
-parserTest = testGroup "parser"
-  [ testGroup "readTix'"
+parserTest = orderedTestGroup "parser"
+  [ orderedTestGroup "readTix'"
     [ testCase "compare" $ do
         let read_with f = f (reciprocal_dir </> "reciprocal.tix")
         tix1 <- read_with readTix
@@ -96,7 +101,7 @@
         assertEqual "readTix'" tix1 tix2
     ]
 
-  , testGroup "readMix'"
+  , orderedTestGroup "readMix'"
     [ testCase "compare" $ do
         let read_with f = f [reciprocal_dir </> ".hpc"] (Left "Main")
         mix1 <- read_with readMix
@@ -134,7 +139,7 @@
   ]
 
 cmdline :: TestTree
-cmdline = testGroup "cmdline"
+cmdline = orderedTestGroup "cmdline"
   [ testCase "non-existing-option"
              (shouldFail (main' ["--foo"]))
   , testCase "non-existing-options"
@@ -157,7 +162,7 @@
   ]
 
 recipReport :: TestTree
-recipReport = testGroup "recip"
+recipReport = orderedTestGroup "recip"
   [ testCase "recip-data-to-stdout"
              (main' ["--mix=test/data/reciprocal/.hpc"
                     ,"--src=test/data/reciprocal"
@@ -186,7 +191,7 @@
   ]
 
 exprOnly :: TestTree
-exprOnly = testGroup "expr-only" $
+exprOnly = orderedTestGroup "expr-only" $
   let eo01_dir = joinPath ["test", "data", "eo01"]
       common_args = ["--mix=" <> (eo01_dir </> ".hpc")
                     ,"--src=" <> eo01_dir
@@ -204,7 +209,7 @@
       ]
 
 ignoreDittos :: TestTree
-ignoreDittos = testGroup "ignore-dittos" $
+ignoreDittos = orderedTestGroup "ignore-dittos" $
   let doGolden name =
         let golden_path = goldenPath (ofile <.> "golden")
             ofile = dir </> name <.> "json"
@@ -218,7 +223,7 @@
         in  goldenVsFile name golden_path ofile act
   in  [ doGolden "ifd01"
       , doGolden "ith01"
-    ]
+      ]
 
 -- Note: Running test to generate .mix and .tix of hpc-codecov package
 -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -326,7 +331,7 @@
                 , sra_build = Just bd }
 
 selfReport :: IO SRA -> TestTree
-selfReport getArgs = testGroup "self"
+selfReport getArgs = orderedTestGroup "self"
   [ testCase "self-data-to-stdout"
              (getArgs >>= sraMain)
   , testCase "self-data-to-stdout-lcov"
@@ -377,8 +382,8 @@
         mapM_ rmdir_in_project1 [".stack-work", "dot-stack-work"]
       cleanUpDirs tree =
         withResource remove_stack_build_dirs do_nothing (\_ -> tree)
-  in  cleanUpDirs $ testGroup "discover_stack"
-        [ testGroup "plain"
+  in  cleanUpDirs $ orderedTestGroup "discover_stack"
+        [ orderedTestGroup "plain"
           [ t "project1"
             [ "--root=" ++ testData "project1"
             , "--verbose"
@@ -386,7 +391,7 @@
             []
           ]
 
-        , testGroup "dot-stack-work"
+        , orderedTestGroup "dot-stack-work"
           [ t "project1"
             [ "--root=" ++ testData "project1"
             , "--verbose"
@@ -396,7 +401,7 @@
             ["--work-dir=dot-stack-work"]
           ]
 
-        , testGroup "lcov"
+        , orderedTestGroup "lcov"
           [ t "project1"
             [ "--root=" ++ testData "project1"
             , "--verbose"
@@ -405,7 +410,7 @@
             []
           ]
 
-        , testGroup "cobertura"
+        , orderedTestGroup "cobertura"
           [ t "project1"
             [ "--root=" ++ testData "project1"
             , "--verbose"
@@ -417,7 +422,7 @@
           ]
 
         , after AllSucceed "cobertura.project1" $
-          testGroup "golden"
+          orderedTestGroup "golden"
           [ let ofile = "project1-refilled.xml"
                 golden_file = goldenPath "project1.xml.golden"
                 golden_path = joinPath ["test", "data", "golden", golden_file]
@@ -435,7 +440,7 @@
               (findUnder (\p -> takeFileName p == "project1-test.tix")
                          (testData "project1" </> ".stack-work"))
               (\_ -> pure ())
-              (\getTixPath -> testCase "project1" $ do
+              (\getTixPath -> testCase "raw-tix-path" $ do
                  tix_path <- fromMaybe "project1-test.tix" <$> getTixPath
                  canonical_tix_path <- canonicalizePath tix_path
                  putStrLn $
@@ -464,7 +469,7 @@
         callProcessIn (testData "project1") "cabal" ["clean"]
       cleanUpDirs tree =
         withResource cabal_clean (const $ pure ()) (const tree)
-  in  cleanUpDirs $ testGroup "discover_cabal"
+  in  cleanUpDirs $ orderedTestGroup "discover_cabal"
         [ t "project1"
           [ "--root=" ++ testData "project1"
           , "--verbose"
@@ -478,7 +483,7 @@
               (findUnder (\p -> takeFileName p == "project1-test.tix")
                 (testData "project1" </> "dist-newstyle"))
               (\_ -> pure ())
-              (\getTixPath -> testCase "project1" $ do
+              (\getTixPath -> testCase "raw-tix-path" $ do
                   tix_path <- fromMaybe "project1-test.tix" <$> getTixPath
                   canonical_tix_path <- canonicalizePath tix_path
                   main' [ "--verbose"
@@ -603,3 +608,11 @@
 goldenPath path
   | os == "mingw32" = path <.> "windows"
   | otherwise = path
+
+#if MIN_VERSION_tasty(1,5,4)
+orderedTestGroup :: String -> [TestTree] -> TestTree
+orderedTestGroup name = dependentTestGroup name AllFinish
+#else
+orderedTestGroup :: String -> [TestTree] -> TestTree
+orderedTestGroup = testGroup
+#endif
diff --git a/test/data/project1/stack.yaml b/test/data/project1/stack.yaml
--- a/test/data/project1/stack.yaml
+++ b/test/data/project1/stack.yaml
@@ -17,7 +17,7 @@
 #
 # resolver: ./custom-snapshot.yaml
 # resolver: https://example.com/snapshots/2018-01-01.yaml
-resolver: lts-24.1
+resolver: lts-24.40
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.