diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,2 +1,7 @@
+# yamlet-1.0.0.1 (2026-10-12)
+* Allow text-iso8601 0.1.1.2, so that yamlet builds together with packages
+  that do not support text-iso8601 0.2 yet. With text-iso8601 0.1, a time of
+  24:00 does not decode.
+
 # yamlet-1.0.0.0 (2026-10-11)
 * Initial release.
diff --git a/tests/Yamlet/Test/Decode/Scalars.hs b/tests/Yamlet/Test/Decode/Scalars.hs
--- a/tests/Yamlet/Test/Decode/Scalars.hs
+++ b/tests/Yamlet/Test/Decode/Scalars.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 module Yamlet.Test.Decode.Scalars
   ( scalarTests
   ) where
@@ -300,10 +302,7 @@
     "fraction of 13 digits"
     (Just (1, 1, "expected a time such as 12:30:00"))
     (errorOf (decodeText @TimeOfDay "12:30:05.1234567890123"))
-  assertEqual
-    "end of a day"
-    (Right (TimeOfDay 24 0 0))
-    (decodeText "24:00")
+  assertEndOfDay
   assertEqual
     "invalid time"
     (Just (1, 1, "expected a time such as 12:30:00"))
@@ -401,3 +400,19 @@
     $ runParser
       (parseYaml @DiffTime)
       (toYaml (Float (Finite (Sci.scientific 0 maxBound))))
+
+-- At top level, because fourmolu cannot format CPP inside a do block.
+assertEndOfDay :: Assertion
+#if MIN_VERSION_text_iso8601(0,2,0)
+assertEndOfDay =
+  assertEqual
+    "end of a day"
+    (Right (TimeOfDay 24 0 0))
+    (decodeText "24:00")
+#else
+assertEndOfDay =
+  assertEqual
+    "end of a day"
+    (Just (1, 1, "expected a time such as 12:30:00"))
+    (errorOf (decodeText @TimeOfDay "24:00"))
+#endif
diff --git a/yamlet.cabal b/yamlet.cabal
--- a/yamlet.cabal
+++ b/yamlet.cabal
@@ -1,10 +1,10 @@
 cabal-version:      3.8
 build-type:         Simple
 name:               yamlet
-version:            1.0.0.0
+version:            1.0.0.1
 license:            BSD-3-Clause
 license-file:       LICENSE
-category:           Text, Data
+category:           YAML
 maintainer:         andrzej@rybczak.net
 author:             Andrzej Rybczak
 synopsis:           A pure, fast and conforming YAML 1.2 library.
@@ -99,7 +99,7 @@
                     , scientific >= 0.3.9
                     , text       >= 2.0.2 && < 3
                     , text-builder-linear >= 0.1.3 && < 0.2
-                    , text-iso8601 >= 0.2
+                    , text-iso8601 >= 0.1.1.2
                     , time       >= 1.11
                     , uuid-types >= 1.0.6
 
@@ -153,6 +153,7 @@
                     , tasty-quickcheck >= 0.8.1
                     , template-haskell
                     , text
+                    , text-iso8601
                     , time
                     , uuid-types
                     , vector