diff --git a/libc/test/src/stdio/CMakeLists.txt b/libc/test/src/stdio/CMakeLists.txt
@@ -14,6 +14,21 @@ add_libc_unittest(
     libc.src.stdio.fwrite
 )
 
+add_libc_unittest(
+  unlocked_fileop_test
+  SUITE
+    libc_stdio_unittests
+  SRCS
+    unlocked_fileop_test.cpp
+  DEPENDS
+    libc.src.stdio.fclose
+    libc.src.stdio.flockfile
+    libc.src.stdio.fopen
+    libc.src.stdio.fread_unlocked
+    libc.src.stdio.funlockfile
+    libc.src.stdio.fwrite_unlocked
+)
+
 add_subdirectory(printf_core)
 
 add_subdirectory(testdata)
diff --git a/libc/test/src/stdio/unlocked_fileop_test.cpp b/libc/test/src/stdio/unlocked_fileop_test.cpp
@@ -0,0 +1,44 @@
+//===-- Unittests for file operations like fopen, flcose etc --------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdio/fclose.h"
+#include "src/stdio/flockfile.h"
+#include "src/stdio/fopen.h"
+#include "src/stdio/fread_unlocked.h"
+#include "src/stdio/funlockfile.h"
+#include "src/stdio/fwrite_unlocked.h"
+#include "utils/UnitTest/Test.h"
+
+#include <stdio.h>
+
+TEST(LlvmLibcFILETest, UnlockedReadAndWrite) {
+  constexpr char FILENAME[] = "testdata/unlocked_read_and_write.test";
+  ::FILE *file = __llvm_libc::fopen(FILENAME, "w");
+  ASSERT_FALSE(file == nullptr);
+  constexpr char CONTENT[] = "1234567890987654321";
+  __llvm_libc::flockfile(file);
+  ASSERT_EQ(sizeof(CONTENT) - 1, __llvm_libc::fwrite_unlocked(
+                                     CONTENT, 1, sizeof(CONTENT) - 1, file));
+  __llvm_libc::funlockfile(file);
+  ASSERT_EQ(0, __llvm_libc::fclose(file));
+
+  file = __llvm_libc::fopen(FILENAME, "r");
+  ASSERT_FALSE(file == nullptr);
+
+  constexpr size_t READ_SIZE = 5;
+  char data[READ_SIZE * 2 + 1];
+  data[READ_SIZE * 2] = '\0';
+  __llvm_libc::flockfile(file);
+  ASSERT_EQ(__llvm_libc::fread_unlocked(data, 1, READ_SIZE, file), READ_SIZE);
+  ASSERT_EQ(__llvm_libc::fread_unlocked(data + READ_SIZE, 1, READ_SIZE, file),
+            READ_SIZE);
+  __llvm_libc::funlockfile(file);
+  ASSERT_STREQ(data, "1234567890");
+
+  ASSERT_EQ(__llvm_libc::fclose(file), 0);
+}