diff --git a/patches/sleuthkit-4.12.1-fatfs_utils.c b/patches/sleuthkit-4.12.1-fatfs_utils.c
new file mode 100644
index 0000000..aefab16
--- /dev/null
+++ b/patches/sleuthkit-4.12.1-fatfs_utils.c
@@ -0,0 +1,18 @@
+diff --git a/tsk/fs/fatfs_utils.c b/tsk/fs/fatfs_utils.c
+index 9495ac923..440b0dff8 100755
+--- a/tsk/fs/fatfs_utils.c
++++ b/tsk/fs/fatfs_utils.c
+@@ -179,8 +179,11 @@ fatfs_dos_2_unix_time(uint16_t date, uint16_t time, uint8_t timetens)
+      * it out */
+     tm1.tm_isdst = -1;
+ 
+-    ret = mktime(&tm1);
+-
++#if defined( _MSC_VER )
++    ret = _mkgmtime(&tm1);
++#else
++    ret = timegm(&tm1);
++#endif
+     if (ret < 0) {
+         if (tsk_verbose)
+             tsk_fprintf(stderr,
diff --git a/setup.py b/setup.py
index a86ded0..f724a71 100755
--- a/setup.py
+++ b/setup.py
@@ -296,7 +296,8 @@ def patch_sleuthkit(self):
         fd.write(data)
 
     patch_files = [
-        "sleuthkit-{0:s}-configure.ac".format(self._SLEUTHKIT_GIT_TAG)]
+        "sleuthkit-{0:s}-configure.ac".format(self._SLEUTHKIT_GIT_TAG),
+        "sleuthkit-{0:s}-fatfs_utils.c".format(self._SLEUTHKIT_GIT_TAG)]
 
     for patch_file in patch_files:
       patch_file = os.path.join("patches", patch_file)
diff --git a/tsk3.cpp b/tsk3.cpp
index 18eca45..a158a44 100644
--- a/tsk3.cpp
+++ b/tsk3.cpp
@@ -695,20 +695,6 @@ VIRTUAL(Volume_Info, Object) {
 
 
 void tsk_init() {
-
-  // libtsk uses mktime and localtime that rely on the TZ environment variable
-  // however that leads to inconsistent behavior with different TZ values.
-  // Hence that we force TZ to be UTC, when possible.
-#if defined( _MSC_VER )
-  _putenv_s("TZ", "UTC");
-  _tzset();
-
-  // Some installations of MinGW do not support setenv
-#elif !defined( __MINGW32__ )
-  setenv("TZ", "UTC", 1);
-  tzset();
-#endif
-
   //tsk_verbose++;
   Img_Info_init((Object)&__Img_Info);
   FS_Info_init((Object)&__FS_Info);