diff --git a/src/Functions/substring.cpp b/src/Functions/substring.cpp
index cc2e1c70fd5..3fe82b5e0b0 100644
--- a/src/Functions/substring.cpp
+++ b/src/Functions/substring.cpp
@@ -91,9 +91,11 @@ public:
             if (column_start_const)
             {
                 if (start_value > 0)
-                    sliceFromLeftConstantOffsetUnbounded(source, StringSink(*col_res, input_rows_count), start_value - 1);
+                    sliceFromLeftConstantOffsetUnbounded(
+                        source, StringSink(*col_res, input_rows_count), static_cast<size_t>(start_value - 1));
                 else if (start_value < 0)
-                    sliceFromRightConstantOffsetUnbounded(source, StringSink(*col_res, input_rows_count), -start_value);
+                    sliceFromRightConstantOffsetUnbounded(
+                        source, StringSink(*col_res, input_rows_count), -static_cast<size_t>(start_value));
                 else
                     throw Exception("Indices in strings are 1-based", ErrorCodes::ZERO_ARRAY_OR_TUPLE_INDEX);
             }
@@ -105,9 +107,11 @@ public:
             if (column_start_const && column_length_const)
             {
                 if (start_value > 0)
-                    sliceFromLeftConstantOffsetBounded(source, StringSink(*col_res, input_rows_count), start_value - 1, length_value);
+                    sliceFromLeftConstantOffsetBounded(
+                        source, StringSink(*col_res, input_rows_count), static_cast<size_t>(start_value - 1), length_value);
                 else if (start_value < 0)
-                    sliceFromRightConstantOffsetBounded(source, StringSink(*col_res, input_rows_count), -start_value, length_value);
+                    sliceFromRightConstantOffsetBounded(
+                        source, StringSink(*col_res, input_rows_count), -static_cast<size_t>(start_value), length_value);
                 else
                     throw Exception("Indices in strings are 1-based", ErrorCodes::ZERO_ARRAY_OR_TUPLE_INDEX);
             }
diff --git a/tests/queries/0_stateless/01665_substring_ubsan.reference b/tests/queries/0_stateless/01665_substring_ubsan.reference
new file mode 100644
index 00000000000..9e5f5f8a47c
--- /dev/null
+++ b/tests/queries/0_stateless/01665_substring_ubsan.reference
@@ -0,0 +1,7 @@
+
+
+
+
+
+
+
diff --git a/tests/queries/0_stateless/01665_substring_ubsan.sql b/tests/queries/0_stateless/01665_substring_ubsan.sql
new file mode 100644
index 00000000000..670998aee31
--- /dev/null
+++ b/tests/queries/0_stateless/01665_substring_ubsan.sql
@@ -0,0 +1 @@
+SELECT substringUTF8(materialize(''), -9223372036854775808) FROM numbers(7);