diff --git a/ascii-superset.cabal b/ascii-superset.cabal
--- a/ascii-superset.cabal
+++ b/ascii-superset.cabal
@@ -1,7 +1,7 @@
 cabal-version: 3.0
 
 name: ascii-superset
-version: 1.1.0.0
+version: 1.1.1.0
 synopsis: Representing ASCII with refined supersets
 category: Data, Text
 
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,7 @@
+### 1.1.1.0 (2023-01-03)
+
+Add to `ASCII.CaseRefinement` the `KnownCase` class.
+
 ### 1.1.0.0 (2023-01-03)
 
 Add classes `ToChar` (`isAsciiChar`, `toCharUnsafe`) and `FromChar`
diff --git a/library/ASCII/CaseRefinement.hs b/library/ASCII/CaseRefinement.hs
--- a/library/ASCII/CaseRefinement.hs
+++ b/library/ASCII/CaseRefinement.hs
@@ -6,6 +6,7 @@
           toCaselessChar, substituteChar, asCaselessChar,
     {- * String functions -} validateString, fromCaselessCharList,
           toCaselessCharList, substituteString, mapChars,
+    {- * KnownCase -} KnownCase (..),
   )
   where