# Allow to set the Gregorian change date for ISO8601 calendars.
#
# ICU bug: https://unicode-org.atlassian.net/browse/ICU-22412

diff --git a/intl/icu/source/i18n/ucal.cpp b/intl/icu/source/i18n/ucal.cpp
--- a/intl/icu/source/i18n/ucal.cpp
+++ b/intl/icu/source/i18n/ucal.cpp
@@ -22,10 +22,11 @@
 #include "unicode/ustring.h"
 #include "unicode/strenum.h"
 #include "unicode/localpointer.h"
 #include "cmemory.h"
 #include "cstring.h"
+#include "iso8601cal.h"
 #include "ustrenum.h"
 #include "uenumimp.h"
 #include "ulist.h"
 #include "ulocimp.h"
 
@@ -305,11 +306,12 @@ ucal_setGregorianChange(UCalendar *cal, 
         // We normally don't check "this" pointers for nullptr, but this here avoids
         // compiler-generated exception-throwing code in case cal == nullptr.
         *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
         return;
     }
-    if(typeid(*cpp_cal) != typeid(GregorianCalendar)) {
+    if(typeid(*cpp_cal) != typeid(GregorianCalendar) &&
+       typeid(*cpp_cal) != typeid(ISO8601Calendar)) {
         *pErrorCode = U_UNSUPPORTED_ERROR;
         return;
     }
     gregocal->setGregorianChange(date, *pErrorCode);
 }
@@ -327,11 +329,12 @@ ucal_getGregorianChange(const UCalendar 
         // We normally don't check "this" pointers for nullptr, but this here avoids
         // compiler-generated exception-throwing code in case cal == nullptr.
         *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
         return (UDate)0;
     }
-    if(typeid(*cpp_cal) != typeid(GregorianCalendar)) {
+    if(typeid(*cpp_cal) != typeid(GregorianCalendar) &&
+       typeid(*cpp_cal) != typeid(ISO8601Calendar)) {
         *pErrorCode = U_UNSUPPORTED_ERROR;
         return (UDate)0;
     }
     return gregocal->getGregorianChange();
 }