1 files changed, 8 insertions, 0 deletions
diff --git a/libc/test/src/string/strtok_r_test.cpp b/libc/test/src/string/strtok_r_test.cpp
index a19390d0b0c2..8c4d3c362f77 100644
--- a/libc/test/src/string/strtok_r_test.cpp
+++ b/libc/test/src/string/strtok_r_test.cpp
@@ -131,3 +131,11 @@ TEST(LlvmLibcStrTokReentrantTest, SubsequentSearchesReturnNull) {
   ASSERT_EQ(LIBC_NAMESPACE::strtok_r(nullptr, ":", &reserve), nullptr);
   ASSERT_EQ(LIBC_NAMESPACE::strtok_r(nullptr, ":", &reserve), nullptr);
 }
+
+TEST(LlvmLibcStrTokReentrantTest, TopBitSet) {
+  char top_bit_set_str[] = "hello\x80world";
+  char *p;
+  ASSERT_STREQ(LIBC_NAMESPACE::strtok_r(top_bit_set_str, "\x80", &p), "hello");
+  ASSERT_STREQ(LIBC_NAMESPACE::strtok_r(nullptr, "\x80", &p), "world");
+  ASSERT_EQ(LIBC_NAMESPACE::strtok_r(nullptr, "\x80", &p), nullptr);
+}