diff --git a/tensorflow/core/kernels/BUILD b/tensorflow/core/kernels/BUILD
index ce56654c883..423bd427534 100644
--- a/tensorflow/core/kernels/BUILD
+++ b/tensorflow/core/kernels/BUILD
@@ -6262,6 +6262,7 @@ filegroup(
         "stateless_random_ops.cc",
         "stateless_random_ops_v2.cc",
         "string_join_op.cc",
+        "string_length_op.cc",
         "string_lower_op.cc",
         "string_util.cc",
         "string_split_op.cc",
diff --git a/tensorflow/lite/delegates/flex/allowlisted_flex_ops.cc b/tensorflow/lite/delegates/flex/allowlisted_flex_ops.cc
index 688212ebcab..266ea093e2f 100644
--- a/tensorflow/lite/delegates/flex/allowlisted_flex_ops.cc
+++ b/tensorflow/lite/delegates/flex/allowlisted_flex_ops.cc
@@ -548,6 +548,7 @@ const std::set<std::string>& GetFlexAllowlist() {
           "StridedSliceAssign",
           "StridedSliceGrad",
           "StringJoin",
+          "StringLength",
           "StringLower",
           "StringSplit",
           "StringSplitV2",