diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 # Revision history for iso8601-duration
 
+## 0.1.2.1  -- 2025-06-26
+
+* Relaxed version bounds and properly specify build-tool-depends
+
+* First version. Released on an unsuspecting world.
 ## 0.1.0.0  -- YYYY-mm-dd
 
 * First version. Released on an unsuspecting world.
diff --git a/iso8601-duration.cabal b/iso8601-duration.cabal
--- a/iso8601-duration.cabal
+++ b/iso8601-duration.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                iso8601-duration
-version:             0.1.2.0
+version:             0.1.2.1
 synopsis:            Types and parser for ISO8601 durations
 description:         Types and parser for ISO8601 durations and intervals
 homepage:            https://github.com/albertov/iso8601-duration
@@ -22,7 +22,7 @@
   -- other-modules:
   other-extensions:    ScopedTypeVariables, OverloadedStrings
   build-depends:       base              >= 4.7    && < 5.0
-                     , bytestring        >= 0.10   && < 0.12
+                     , bytestring        >= 0.10   && < 0.13
                      , attoparsec        >= 0.13.1 && < 0.15
                      , time              >= 1.8    && < 1.13
                      , bytestring-lexing >= 0.5    && < 0.6
@@ -34,6 +34,7 @@
 
 test-suite spec
   type:                exitcode-stdio-1.0
+  build-tool-depends:  hspec-discover:hspec-discover
   build-depends:       base
                      , bytestring
                      , time