diff --git a/libs/contrib/Text/Distance/Levenshtein.idr b/libs/contrib/Text/Distance/Levenshtein.idr
index 83102786e0..903bb51dcc 100644
--- a/libs/contrib/Text/Distance/Levenshtein.idr
+++ b/libs/contrib/Text/Distance/Levenshtein.idr
@@ -10,7 +10,7 @@ import Data.List.Extra
 
 ||| Self-evidently correct but O(3 ^ (min mn)) complexity
 spec : String -> String -> Nat
-spec a b = loop (fastUnpack a) (fastUnpack b) where
+spec a b = loop (unpack a) (unpack b) where
 
   loop : List Char -> List Char -> Nat
   loop [] ys = length ys -- deletions
diff --git a/libs/contrib/Text/Lexer/Core.idr b/libs/contrib/Text/Lexer/Core.idr
index be91d372c4..6fde0660b9 100644
--- a/libs/contrib/Text/Lexer/Core.idr
+++ b/libs/contrib/Text/Lexer/Core.idr
@@ -159,7 +159,7 @@ tokenise pred line col acc tmap str
                Just (tok, rest) =>
                  let line' = line + cast (countNLs tok)
                      col' = getCols tok col in
-                     Just (MkBounded (fn (fastPack (reverse tok))) False (MkBounds line col line' col'),
+                     Just (MkBounded (fn (pack (reverse tok))) False (MkBounds line col line' col'),
                            line', col', rest)
                Nothing => getFirstToken ts str
 
@@ -171,11 +171,11 @@ export
 lex : TokenMap a -> String -> (List (WithBounds a), (Int, Int, String))
 lex tmap str
     = let (ts, (l, c, str')) = tokenise (const False) 0 0 [] tmap (unpack str) in
-          (ts, (l, c, fastPack str'))
+          (ts, (l, c, pack str'))
 
 export
 lexTo : (a -> Bool) ->
         TokenMap a -> String -> (List (WithBounds a), (Int, Int, String))
 lexTo pred tmap str
     = let (ts, (l, c, str')) = tokenise pred 0 0 [] tmap (unpack str) in
-          (ts, (l, c, fastPack str'))
+          (ts, (l, c, pack str'))
diff --git a/libs/contrib/Text/Lexer/Tokenizer.idr b/libs/contrib/Text/Lexer/Tokenizer.idr
index f9d9bc8169..5fb4bb287b 100644
--- a/libs/contrib/Text/Lexer/Tokenizer.idr
+++ b/libs/contrib/Text/Lexer/Tokenizer.idr
@@ -110,7 +110,7 @@ tokenise reject tokenizer line col acc str
             | _ => Nothing
           line' = line + cast (countNLs token)
           col' = getCols token col
-          tokenStr = fastPack $ reverse token
+          tokenStr = pack $ reverse token
        in pure (tokenStr, line', col', rest)
 
     getFirstMatch : Tokenizer a -> List Char ->
@@ -149,8 +149,8 @@ lexTo : Lexer ->
         (List (WithBounds a), (StopReason, Int, Int, String))
 lexTo reject tokenizer str
     = let (ts, reason, (l, c, str')) =
-              tokenise reject tokenizer 0 0 [] (fastUnpack str) in
-          (ts, reason, (l, c, fastPack str'))
+              tokenise reject tokenizer 0 0 [] (unpack str) in
+          (ts, reason, (l, c, pack str'))
 
 ||| Given a tokenizer and an input string, return a list of recognised tokens,
 ||| and the line, column, and remainder of the input at the first point in the string
diff --git a/libs/contrib/Text/Literate.idr b/libs/contrib/Text/Literate.idr
index ca52b9ca31..eecf5fb6ae 100644
--- a/libs/contrib/Text/Literate.idr
+++ b/libs/contrib/Text/Literate.idr
@@ -78,7 +78,7 @@ namespace Compat
 
 ||| Merge the tokens into a single source file.
 reduce : List (WithBounds Token) -> List String -> String
-reduce [] acc = fastConcat (reverse acc)
+reduce [] acc = concat (reverse acc)
 reduce (MkBounded (Any x) _ _ :: rest) acc =
   -- newline will always be tokenized as a single token
   if x == "\n"
diff --git a/libs/contrib/Text/PrettyPrint/Prettyprinter/Render/HTML.idr b/libs/contrib/Text/PrettyPrint/Prettyprinter/Render/HTML.idr
index e772b79e9e..c457474c5f 100644
--- a/libs/contrib/Text/PrettyPrint/Prettyprinter/Render/HTML.idr
+++ b/libs/contrib/Text/PrettyPrint/Prettyprinter/Render/HTML.idr
@@ -6,7 +6,7 @@ import Data.String
 
 export
 htmlEscape : String -> String
-htmlEscape s = fastConcat $ reverse $ go [] s
+htmlEscape s = concat $ reverse $ go [] s
   where
     isSafe : Char -> Bool
     isSafe '"' = False