diff --git a/base/common/DateLUTImpl.h b/base/common/DateLUTImpl.h
index 43fc1b8befd..1a44c670650 100644
--- a/base/common/DateLUTImpl.h
+++ b/base/common/DateLUTImpl.h
@@ -1073,7 +1073,7 @@ public:
     {
         const Values & values = lut[toLUTIndex(v)];
 
-        Int64 month = static_cast<Int64>(values.month) + delta;
+        Int64 month = values.month + static_cast<UInt64>(delta);    /// Cast is to avoid UB in signed integer overflow.
 
         if (month > 0)
         {
diff --git a/tests/queries/0_stateless/01770_add_months_ubsan.reference b/tests/queries/0_stateless/01770_add_months_ubsan.reference
new file mode 100644
index 00000000000..573541ac970
--- /dev/null
+++ b/tests/queries/0_stateless/01770_add_months_ubsan.reference
@@ -0,0 +1 @@
+0
diff --git a/tests/queries/0_stateless/01770_add_months_ubsan.sql b/tests/queries/0_stateless/01770_add_months_ubsan.sql
new file mode 100644
index 00000000000..039434ff9bc
--- /dev/null
+++ b/tests/queries/0_stateless/01770_add_months_ubsan.sql
@@ -0,0 +1,2 @@
+-- Result does not make sense but UBSan report should not be triggered.
+SELECT ignore(now() + INTERVAL 9223372036854775807 MONTH);