diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Revision history for svgsym
 
-## 0.1.0.0 -- YYYY-mm-dd
+## 0.1.1.0 -- 2022-05-07
+
+* Expand allowed versions of the base library.
+  Mainly to support builds using GHC 8.10.
+
+* Validate symbol ID regular expression before use.
+
+## 0.1.0.0 -- 2022-05-01
 
 * First version. Released on an unsuspecting world.
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@
 symbol regular expression consist of a single capture group that
 captures the actual symbol identifier.
 
-``` sh-session
+``` console
 $ svgsym css-gg/all.svg \
     --content './src/**/*.hs' \
     --symbol '"(gg-[a-z]+)"' \
diff --git a/src-exe/Main.hs b/src-exe/Main.hs
--- a/src-exe/Main.hs
+++ b/src-exe/Main.hs
@@ -1,11 +1,14 @@
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 
-module Main where
+module Main (main) where
 
 import Control.Monad (forM, when)
+import Data.Array ((!))
+import qualified Data.Array as Arr
 import qualified Data.ByteString.Lazy as LB
 import Data.Foldable (Foldable (fold), find, for_)
 import Data.List (isPrefixOf)
@@ -21,10 +24,19 @@
 import System.FilePath ((</>))
 import System.FilePattern.Directory (FilePattern, getDirectoryFiles)
 import System.IO (hPutStrLn, stderr)
-import Text.Regex.TDFA (AllTextMatches (getAllTextMatches), (=~))
+import Text.Regex.TDFA (AllTextMatches (getAllTextMatches), Regex, RegexContext (match), RegexLike (matchAll, matchAllText), makeRegexM, (=~), (=~~))
+import Text.Regex.TDFA.Common (Regex (regex_groups))
 import Text.XML.Light (Attr (Attr), Element (Element, elContent, elName), QName (..), parseXMLDoc, ppTopElement, showElement)
 import qualified Text.XML.Light as Xml
 
+type Re = String
+
+newtype Errorable a = Errorable (Either String a)
+  deriving (Functor, Applicative, Monad)
+
+instance MonadFail Errorable where
+  fail = Errorable . Left
+
 qnSvg :: QName
 qnSvg = QName {qName = "svg", qURI = Just "http://www.w3.org/2000/svg", qPrefix = Nothing}
 
@@ -54,13 +66,12 @@
     }
 
 -- | Find all symbols using the given pattern
-findSymbols :: String -> String -> Set String
-findSymbols pat haystack = Set.fromList $ go haystack
+findSymbols :: Regex -> String -> Set String
+findSymbols regex = Set.fromList . concatMap go . lines
   where
+    go :: String -> [String]
     go "" = []
-    go s =
-      let (_, _, rest, match) = s =~ pat :: (String, String, String, [String])
-       in match <> go rest
+    go s = map (fst . (! 1)) $ matchAllText regex s
 
 findFiles :: [FilePattern] -> IO [FilePath]
 findFiles patterns = do
@@ -71,7 +82,7 @@
       absPats = makeAbsolute <$> patterns
   getDirectoryFiles "/" absPats
 
-findFileSymbols :: String -> [FilePath] -> IO (Set String)
+findFileSymbols :: Regex -> [FilePath] -> IO (Set String)
 findFileSymbols regex files = do
   fmap fold . forM files $ \f -> do
     s <- readFile f
@@ -98,13 +109,26 @@
 main :: IO ()
 main = do
   Opts.Options {..} <- execParser Opts.parser
+
+  symbolRegex <- case makeRegexM symbolPat of
+    Errorable (Left err) -> do
+      hPutStrLn stderr "Errorable parsing symbol regular expression:"
+      hPutStrLn stderr err
+      exitFailure
+    Errorable (Right re) -> do
+      let (_, n) = Arr.bounds $ regex_groups re
+      when (n /= 1) do
+        hPutStrLn stderr "Expect exactly one capture group in symbol regular expression."
+        exitFailure
+      pure re
+
   files <- findFiles contentPats
 
   when debug do
     hPutStrLn stderr "Matched content files:"
     for_ files \f -> hPutStrLn stderr ("  " <> f)
 
-  symbols <- findFileSymbols symbolPat files
+  symbols <- findFileSymbols symbolRegex files
 
   when debug do
     hPutStrLn stderr "Matched symbols:"
diff --git a/svgsym.cabal b/svgsym.cabal
--- a/svgsym.cabal
+++ b/svgsym.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               svgsym
-version:            0.1.0.0
+version:            0.1.1.0
 synopsis:           A tool to prune unused symbols from icon SVG files.
 homepage:           https://git.sr.ht/~rycee/svgsym
 bug-reports:        https://lists.sr.ht/~rycee/public-inbox
@@ -22,13 +22,15 @@
     Svgsym.Options
 
   build-depends:
-    , base                  ^>=4.15.1
+    , array                 ^>=0.5
+    , base                  >=4.14  && <4.17
     , bytestring            ^>=0.10
     , containers            ^>=0.6
     , directory             ^>=1.3
     , filepath              ^>=1.4
     , filepattern           ^>=0.1.2
     , optparse-applicative  ^>=0.16
+    , regex-base            ^>=0.94
     , regex-tdfa            ^>=1.3.1
     , xml                   ^>=1.3