diff --git a/ascii.cabal b/ascii.cabal
--- a/ascii.cabal
+++ b/ascii.cabal
@@ -1,7 +1,7 @@
 cabal-version: 3.0
 
 name: ascii
-version: 1.1.3.0
+version: 1.2.0.0
 synopsis: The ASCII character set and encoding
 category: Data, Text
 
@@ -43,37 +43,38 @@
 
     exposed-modules: ASCII
 
-    build-depends: ascii-char ^>= 1.0
+    build-depends: ascii-char == 1.0.0.*
     reexported-modules:
         ASCII.Char
 
-    build-depends: ascii-group ^>= 1.0
+    build-depends: ascii-group == 1.0.0.*
     reexported-modules:
         ASCII.Group
 
-    build-depends: ascii-case ^>= 1.0
+    build-depends: ascii-case == 1.0.0.*
     reexported-modules:
         ASCII.Case
 
-    build-depends: ascii-numbers ^>= 1.0
+    build-depends: ascii-numbers == 1.1.0.*
     reexported-modules:
         ASCII.Decimal
       , ASCII.Hexadecimal
+      , ASCII.Word4
 
-    build-depends: ascii-predicates ^>= 1.0
+    build-depends: ascii-predicates == 1.0.0.*
     reexported-modules:
         ASCII.Predicates
       , ASCII.Lists
       , ASCII.ListsAndPredicates
 
-    build-depends: ascii-superset ^>= 1.0.1
+    build-depends: ascii-superset == 1.0.1.*
     reexported-modules:
         ASCII.Superset
       , ASCII.Isomorphism
       , ASCII.Refinement
       , ASCII.Lift
 
-    build-depends: ascii-th ^>= 1.0
+    build-depends: ascii-th == 1.0.0.*
     reexported-modules:
         ASCII.TemplateHaskell
       , ASCII.QuasiQuoters
diff --git a/library/ASCII.hs b/library/ASCII.hs
--- a/library/ASCII.hs
+++ b/library/ASCII.hs
@@ -82,7 +82,7 @@
 
 import ASCII.Case (Case (..))
 import ASCII.Char (Char)
-import ASCII.Decimal (D10, DigitStringSuperset, DigitSuperset)
+import ASCII.Decimal (Digit, DigitStringSuperset, DigitSuperset)
 import ASCII.Group (Group (..))
 import ASCII.Hexadecimal (HexChar, HexCharSuperset, HexStringSuperset)
 import ASCII.Isomorphism (CharIso, StringIso)
@@ -652,16 +652,6 @@
 See also: "ASCII.Decimal"
 
 -}
-
-{- |
-
-The subset of ASCII used to represent unsigned decimal numbers:
-
-* 'ASCII.Char.Digit0' to 'ASCII.Char.Digit9'
-
--}
-
-type Digit = D10
 
 {- $hexchar