diff --git a/contrib/cctz b/contrib/cctz
index 8529bcef5cd..7918cb7afe8 160000
--- a/contrib/cctz
+++ b/contrib/cctz
@@ -1 +1 @@
-Subproject commit 8529bcef5cd996b7c0f4d7475286b76b5d126c4c
+Subproject commit 7918cb7afe82e53428e39a045a437fdfd4f3df47
diff --git a/src/Core/SettingsFields.cpp b/src/Core/SettingsFields.cpp
index e514ced6f68..001d3e09dc9 100644
--- a/src/Core/SettingsFields.cpp
+++ b/src/Core/SettingsFields.cpp
@@ -8,7 +8,9 @@
 #include <IO/ReadHelpers.h>
 #include <IO/ReadBufferFromString.h>
 #include <IO/WriteHelpers.h>
+
 #include <boost/algorithm/string/predicate.hpp>
+#include <cctz/time_zone.h>
 
 #include <cmath>
 
@@ -544,6 +546,13 @@ void SettingFieldTimezone::readBinary(ReadBuffer & in)
     *this = std::move(str);
 }
 
+void SettingFieldTimezone::validateTimezone(const std::string & tz_str)
+{
+    cctz::time_zone validated_tz;
+    if (!tz_str.empty() && !cctz::load_time_zone(tz_str, &validated_tz))
+        throw DB::Exception(DB::ErrorCodes::BAD_ARGUMENTS, "Invalid time zone: {}", tz_str);
+}
+
 String SettingFieldCustom::toString() const
 {
     return value.dump();
diff --git a/src/Core/SettingsFields.h b/src/Core/SettingsFields.h
index 22c1cf8a267..452f3f149ab 100644
--- a/src/Core/SettingsFields.h
+++ b/src/Core/SettingsFields.h
@@ -6,7 +6,6 @@
 #include <Core/Field.h>
 #include <Core/MultiEnum.h>
 #include <boost/range/adaptor/map.hpp>
-#include <cctz/time_zone.h>
 #include <chrono>
 #include <unordered_map>
 #include <string_view>
@@ -608,12 +607,7 @@ struct SettingFieldTimezone
     void readBinary(ReadBuffer & in);
 
 private:
-    void validateTimezone(const std::string & tz_str)
-    {
-        cctz::time_zone validated_tz;
-        if (!tz_str.empty() && !cctz::load_time_zone(tz_str, &validated_tz))
-            throw DB::Exception(DB::ErrorCodes::BAD_ARGUMENTS, "Invalid time zone: {}", tz_str);
-    }
+    void validateTimezone(const std::string & tz_str);
 };
 
 /// Can keep a value of any type. Used for user-defined settings.