1 files changed, 4 insertions, 0 deletions
diff --git a/native/jni/src/utils/char_utils.h b/native/jni/src/utils/char_utils.h
index f28ed5682..63786502b 100644
--- a/native/jni/src/utils/char_utils.h
+++ b/native/jni/src/utils/char_utils.h
@@ -98,6 +98,10 @@ class CharUtils {
     // Beginning-of-Sentence.
     static AK_FORCE_INLINE int attachBeginningOfSentenceMarker(int *const codePoints,
             const int codePointCount, const int maxCodePoint) {
+        if (codePointCount > 0 && codePoints[0] == CODE_POINT_BEGINNING_OF_SENTENCE) {
+            // Marker has already been attached.
+            return codePointCount;
+        }
         if (codePointCount >= maxCodePoint) {
             // the code points cannot be marked as a Beginning-of-Sentence.
             return 0;