diff --git a/ChangeLog.md b/ChangeLog.md
new file mode 100644
--- /dev/null
+++ b/ChangeLog.md
@@ -0,0 +1,7 @@
+# ChangeLog for unix-time
+
+## v0.4.16
+
+* Make `tzset` optional.
+  [#65](https://github.com/kazu-yamamoto/unix-time/pull/65)
+
diff --git a/cbits/conv.c b/cbits/conv.c
--- a/cbits/conv.c
+++ b/cbits/conv.c
@@ -55,7 +55,9 @@
 #else
     setenv("TZ", "", 1);
 #endif
+#if defined(HAVE_TZSET)
     tzset();
+#endif
     return tz;
 }
 
@@ -77,7 +79,9 @@
       unsetenv("TZ");
 #endif
     }
+#if defined(HAVE_TZSET)
     tzset();
+#endif
 }
 
 time_t c_parse_unix_time(char *fmt, char *src) {
diff --git a/unix-time.cabal b/unix-time.cabal
--- a/unix-time.cabal
+++ b/unix-time.cabal
@@ -1,6 +1,6 @@
 cabal-version:      1.18
 name:               unix-time
-version:            0.4.15
+version:            0.4.16
 license:            BSD3
 license-file:       LICENSE
 maintainer:         Kazu Yamamoto <kazu@iij.ad.jp>
@@ -25,6 +25,8 @@
     autom4te.cache
     cbits/config.h
 
+extra-doc-files:    ChangeLog.md
+
 source-repository head
     type:     git
     location: https://github.com/kazu-yamamoto/unix-time
@@ -51,17 +53,8 @@
     if impl(ghc >=7.8)
         cc-options: -fPIC
 
-    -- GHC 9.4.5, 9.6.1, and 9.6.2 on Windows do not link against mingwex, but
-    -- unix-time implicitly depends on this library due to the use of the
-    -- gettimeofday() function, which comes from mingwex on Windows. To avoid
-    -- linker errors in the absence of a mingwex dependency (see
-    -- https://gitlab.haskell.org/ghc/ghc/-/issues/23533 for an example of
-    -- this), we depend on mingwex explicitly here.
-    --
-    -- Other versions of GHC on Windows already depend on mingwex, so we guard
-    -- this behind appropriate conditionals.
     if os(windows)
-        if (impl(ghc >= 9.4.5) && !impl(ghc >= 9.4.6)) || (impl(ghc >= 9.6.1) && !impl(ghc >= 9.6.3))
+        if ((impl(ghc >=9.4.5) && !impl(ghc >=9.4.6)) || (impl(ghc >=9.6.1) && !impl(ghc >=9.6.3)))
             extra-libraries: mingwex
 
     if os(windows)