diff --git a/HTF.cabal b/HTF.cabal
--- a/HTF.cabal
+++ b/HTF.cabal
@@ -1,5 +1,5 @@
 Name:             HTF
-Version:          0.14.0.5
+Version:          0.14.0.6
 License:          LGPL-2.1
 License-File:     LICENSE
 Copyright:        (c) 2005-2015 Stefan Wehr
@@ -84,12 +84,20 @@
   scripts/run-sample
   scripts/prepare
 
+tested-with:
+  GHC == 8.2.2
+  GHC == 8.4.4
+  GHC == 8.6.5
+  GHC == 8.8.4
+  GHC == 8.10.4
+  GHC == 9.0.1
+
 Source-Repository head
   Type:           git
   Location:       http://github.com/skogsbaer/HTF.git
 
 Custom-Setup
-  Setup-Depends:   base == 4.*,
+  Setup-Depends:   base >= 4.10 && < 5,
                    process,
                    Cabal
 
@@ -97,7 +105,7 @@
   Main-Is:          HTFPP.hs
   Build-Depends:    HUnit,
                     array,
-                    base == 4.*,
+                    base >= 4.10 && < 5,
                     cpphs >= 1.19,
                     directory >= 1.0,
                     mtl >= 1.1,
@@ -120,7 +128,7 @@
                     QuickCheck >= 2.3,
                     aeson >= 0.11,
                     array,
-                    base == 4.*,
+                    base >= 4.10 && < 5,
                     base64-bytestring,
                     bytestring >= 0.9,
                     containers >= 0.5,
@@ -179,7 +187,7 @@
   Hs-Source-Dirs:    tests
   Build-depends:     HTF,
                      HUnit,
-                     base == 4.*,
+                     base >= 4.10 && < 5,
                      mtl,
                      random
   Build-tool-depends: HTF:htfpp
@@ -192,7 +200,7 @@
   Build-depends:     HTF,
                      aeson >= 0.6,
                      aeson-pretty,
-                     base == 4.*,
+                     base >= 4.10 && < 5,
                      bytestring >= 0.9,
                      directory >= 1.0,
                      filepath >= 1.1,
@@ -215,7 +223,7 @@
   Type:              exitcode-stdio-1.0
   Hs-Source-Dirs:    tests
   Build-depends:     HTF,
-                     base == 4.*,
+                     base >= 4.10 && < 5,
                      mtl,
                      random
   Build-tool-depends: HTF:htfpp
diff --git a/Test/Framework/History.hs b/Test/Framework/History.hs
--- a/Test/Framework/History.hs
+++ b/Test/Framework/History.hs
@@ -103,6 +103,28 @@
 _CURRENT_VERSION_ :: Int
 _CURRENT_VERSION_ = 0
 
+instance ToJSON TestResult where
+    toJSON r = String $
+        case L.lookup r testResultStringMapping of
+          Just s -> s
+          Nothing -> error ("TestResult " ++ show r ++ " not defined in testResultStringMapping")
+
+instance FromJSON TestResult where
+    parseJSON v =
+        case v of
+          String s
+              | Just r <- L.lookup s (map (\(x, y) -> (y, x)) testResultStringMapping)
+                       -> return r
+          _ -> fail ("could not parse JSON value as a test result: " ++ show v)
+
+testResultStringMapping :: [(TestResult, T.Text)]
+testResultStringMapping =
+    [(Pass, "pass"), (Pending, "pending"), (Fail, "fail"), (Error, "error")]
+
+deriveJSON (defaultOptions { fieldLabelModifier = drop 4 }) ''HistoricTestResult
+deriveJSON (defaultOptions { fieldLabelModifier = drop 4 }) ''TestRunHistory
+deriveJSON (defaultOptions { fieldLabelModifier = drop 4 }) ''SerializableTestHistory
+
 serializeTestHistory :: TestHistory -> BS.ByteString
 serializeTestHistory hist =
     let serHist = SerializableTestHistory {
@@ -139,25 +161,3 @@
       mkRes id ms = HistoricTestResult id Pass False ms
 
 historyTests = [("testCreateIndex", testCreateIndex)]
-
-testResultStringMapping :: [(TestResult, T.Text)]
-testResultStringMapping =
-    [(Pass, "pass"), (Pending, "pending"), (Fail, "fail"), (Error, "error")]
-
-instance ToJSON TestResult where
-    toJSON r = String $
-        case L.lookup r testResultStringMapping of
-          Just s -> s
-          Nothing -> error ("TestResult " ++ show r ++ " not defined in testResultStringMapping")
-
-instance FromJSON TestResult where
-    parseJSON v =
-        case v of
-          String s
-              | Just r <- L.lookup s (map (\(x, y) -> (y, x)) testResultStringMapping)
-                       -> return r
-          _ -> fail ("could not parse JSON value as a test result: " ++ show v)
-
-deriveJSON (defaultOptions { fieldLabelModifier = drop 4 }) ''SerializableTestHistory
-deriveJSON (defaultOptions { fieldLabelModifier = drop 4 }) ''TestRunHistory
-deriveJSON (defaultOptions { fieldLabelModifier = drop 4 }) ''HistoricTestResult