diff --git a/Criterion/Analysis.hs b/Criterion/Analysis.hs
--- a/Criterion/Analysis.hs
+++ b/Criterion/Analysis.hs
@@ -157,8 +157,10 @@
   rs <- mapM (\(ps,r) -> regress gen ps r meas) $
         ((["iters"],"time"):regressions)
   resamps <- liftIO $ resample gen ests resamples stime
-  let [estMean,estStdDev] = B.bootstrapBCA confInterval stime resamps
-      ov = outlierVariance estMean estStdDev (fromIntegral n)
+  (estMean,estStdDev) <- case B.bootstrapBCA confInterval stime resamps of
+    [estMean',estStdDev'] -> return (estMean',estStdDev')
+    ests' -> throwE $ "analyseSample: Expected two estimation functions, received: " ++ show ests'
+  let ov = outlierVariance estMean estStdDev (fromIntegral n)
       an = SampleAnalysis {
                anRegress    = rs
              , anMean       = estMean
@@ -193,7 +195,9 @@
   let unmeasured = [n | (n, Nothing) <- map (second ($ G.head meas)) accs]
   unless (null unmeasured) $
     throwE $ "no data available for " ++ renderNames unmeasured
-  let (r:ps)      = map ((`measure` meas) . (fromJust .) . snd) accs
+  (r,ps) <- case map ((`measure` meas) . (fromJust .) . snd) accs of
+    (r':ps') -> return (r',ps')
+    []       -> throwE "regress: Expected at least one accessor"
   Config{..} <- ask
   (coeffs,r2) <- liftIO $
                  bootstrapRegress gen resamples confInterval olsRegress ps r
diff --git a/Criterion/Main/Options.hs b/Criterion/Main/Options.hs
--- a/Criterion/Main/Options.hs
+++ b/Criterion/Main/Options.hs
@@ -133,7 +133,8 @@
   <*> option (range 1 1000000)
       (long "resamples" <> metavar "COUNT" <> value resamples <>
        help "Number of bootstrap resamples to perform")
-  <*> many (option regressParams
+  <*> manyDefault regressions
+           (option regressParams
             (long "regress" <> metavar "RESP:PRED.." <>
              help "Regressions to perform"))
   <*> outputOption rawDataFile (long "raw" <>
@@ -153,6 +154,12 @@
   <*> strOption (long "template" <> short 't' <> metavar "FILE" <>
                  value template <>
                  help "Template to use for report")
+
+manyDefault :: [a] -> Parser a -> Parser [a]
+manyDefault def m = set_default <$> many m
+  where
+    set_default [] = def
+    set_default xs = xs
 
 outputOption :: Maybe String -> Mod OptionFields String -> Parser (Maybe String)
 outputOption file m =
diff --git a/README.markdown b/README.markdown
--- a/README.markdown
+++ b/README.markdown
@@ -1,6 +1,6 @@
 # Criterion: robust, reliable performance measurement
 
-[![Hackage](https://img.shields.io/hackage/v/criterion.svg)](https://hackage.haskell.org/package/criterion) [![Build Status](https://travis-ci.org/bos/criterion.svg?branch=master)](https://travis-ci.org/bos/criterion)
+[![Hackage](https://img.shields.io/hackage/v/criterion.svg)](https://hackage.haskell.org/package/criterion) [![Build Status](https://github.com/haskell/criterion/workflows/Haskell-CI/badge.svg)](https://github.com/haskell/criterion/actions?query=workflow%3AHaskell-CI)
 
 This package provides the Criterion module, a Haskell library for
 measuring and analysing software performance.
@@ -24,18 +24,11 @@
 # Get involved!
 
 Please report bugs via the
-[github issue tracker](https://github.com/bos/criterion/issues).
-
-Master [github repository](https://github.com/bos/criterion):
-
-* `git clone https://github.com/bos/criterion.git`
-
-There's also a [Mercurial mirror](https://bitbucket.org/bos/criterion):
-
-* `hg clone https://bitbucket.org/bos/criterion`
+[github issue tracker](https://github.com/haskell/criterion/issues).
 
-(You can create and contribute changes using either Mercurial or git.)
+Master [github repository](https://github.com/haskell/criterion):
 
+* `git clone https://github.com/haskell/criterion.git`
 
 # Authors
 
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,10 @@
+1.5.10.0
+
+* Fix a bug in which the `defaultMainWith` function would not use the
+  `regressions` values specified in the `Config` argument. This bug only
+  affected `criterion` the library—uses of the `--regressions` flag from
+  `criterion` executables themselves were unaffected.
+
 1.5.9.0
 
 * Fix a bug where HTML reports failed to escape JSON properly.
diff --git a/criterion.cabal b/criterion.cabal
--- a/criterion.cabal
+++ b/criterion.cabal
@@ -1,5 +1,5 @@
 name:           criterion
-version:        1.5.9.0
+version:        1.5.10.0
 synopsis:       Robust, reliable performance measurement and analysis
 license:        BSD3
 license-file:   LICENSE
@@ -8,7 +8,7 @@
 copyright:      2009-2016 Bryan O'Sullivan and others
 category:       Development, Performance, Testing, Benchmarking
 homepage:       http://www.serpentine.com/criterion
-bug-reports:    https://github.com/bos/criterion/issues
+bug-reports:    https://github.com/haskell/criterion/issues
 build-type:     Simple
 cabal-version:  >= 1.10
 extra-source-files:
@@ -26,8 +26,9 @@
   GHC==8.2.2,
   GHC==8.4.4,
   GHC==8.6.5,
-  GHC==8.8.3,
-  GHC==8.10.1
+  GHC==8.8.4,
+  GHC==8.10.4,
+  GHC==9.0.1
 
 data-files:
   templates/*.css
@@ -79,7 +80,7 @@
     Paths_criterion
 
   build-depends:
-    aeson >= 0.8,
+    aeson >= 1,
     ansi-wl-pprint >= 0.6.7.2,
     base >= 4.5 && < 5,
     base-compat-batteries >= 0.10 && < 0.12,
@@ -218,4 +219,4 @@
 
 source-repository head
   type:     git
-  location: https://github.com/bos/criterion.git
+  location: https://github.com/haskell/criterion.git
diff --git a/examples/ConduitVsPipes.hs b/examples/ConduitVsPipes.hs
--- a/examples/ConduitVsPipes.hs
+++ b/examples/ConduitVsPipes.hs
@@ -1,5 +1,5 @@
 -- Contributed by Gabriel Gonzales as a test case for
--- https://github.com/bos/criterion/issues/35
+-- https://github.com/haskell/criterion/issues/35
 --
 -- The numbers reported by this benchmark can be made "more correct"
 -- by compiling with the -fno-full-laziness option.
diff --git a/examples/Overhead.hs b/examples/Overhead.hs
--- a/examples/Overhead.hs
+++ b/examples/Overhead.hs
@@ -14,11 +14,11 @@
   M.initializeTime -- Need to do this before calling M.getTime
   statsEnabled <- getRTSStatsEnabled
   defaultMain $ [
-      bench "measure" $            whnfIO (M.measure (whnfIO $ return ()) 1)
-    , bench "getTime" $            whnfIO M.getTime
-    , bench "getCPUTime" $         whnfIO M.getCPUTime
-    , bench "getCycles" $          whnfIO M.getCycles
-    , bench "M.getGCStatisticss" $ whnfIO M.getGCStatistics
+      bench "measure" $           whnfIO (M.measure (whnfIO $ return ()) 1)
+    , bench "getTime" $           whnfIO M.getTime
+    , bench "getCPUTime" $        whnfIO M.getCPUTime
+    , bench "getCycles" $         whnfIO M.getCycles
+    , bench "M.getGCStatistics" $ whnfIO M.getGCStatistics
     ] ++ if statsEnabled
          then [bench
 #if MIN_VERSION_base(4,10,0)
diff --git a/examples/criterion-examples.cabal b/examples/criterion-examples.cabal
--- a/examples/criterion-examples.cabal
+++ b/examples/criterion-examples.cabal
@@ -2,7 +2,7 @@
 version:       0
 synopsis:      Examples for the criterion benchmarking system
 description:   Examples for the criterion benchmarking system.
-homepage:      https://github.com/bos/criterion
+homepage:      https://github.com/haskell/criterion
 license:       BSD3
 license-file:  LICENSE
 author:        Bryan O'Sullivan <bos@serpentine.com>
@@ -19,8 +19,9 @@
   GHC==8.2.2,
   GHC==8.4.4,
   GHC==8.6.5,
-  GHC==8.8.3,
-  GHC==8.10.1
+  GHC==8.8.4,
+  GHC==8.10.4,
+  GHC==9.0.1
 
 flag conduit-vs-pipes
   default: True