diff --git a/jdk-annotations/java/io/annotations.xml b/jdk-annotations/java/io/annotations.xml
index b0e3383d32f..5e50633b65a 100644
--- a/jdk-annotations/java/io/annotations.xml
+++ b/jdk-annotations/java/io/annotations.xml
@@ -1,127 +1,321 @@
 <root>
-    <item name='java.io.File separator'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File pathSeparator'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File File(java.lang.String) 0'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File File(java.lang.String, java.lang.String) 1'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File File(java.lang.String, java.lang.String) 0'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-    </item>
-    <item name='java.io.File File(java.io.File, java.lang.String) 0'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-    </item>
-    <item name='java.io.File File(java.io.File, java.lang.String) 1'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File File(java.net.URI) 0'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.lang.String getName()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.lang.String getParent()'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-    </item>
-    <item name='java.io.File java.io.File getParentFile()'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-    </item>
-    <item name='java.io.File java.lang.String getPath()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.lang.String getAbsolutePath()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.io.File getAbsoluteFile()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.lang.String getCanonicalPath()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.io.File getCanonicalFile()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File @java.lang.Deprecated java.net.URL toURL()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.net.URI toURI()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.lang.String[] list()'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-        <annotation name='jet.runtime.typeinfo.KotlinSignature'>
-            <val name="value" val="&quot;fun list() : Array&lt;String&gt;?&quot;"/>
-        </annotation>
-    </item>
-    <item name='java.io.File java.lang.String[] list(java.io.FilenameFilter) 0'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-    </item>
-    <item name='java.io.File java.lang.String[] list(java.io.FilenameFilter)'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-        <annotation name='jet.runtime.typeinfo.KotlinSignature'>
-            <val name="value" val="&quot;fun list(filter : FilenameFilter?) : Array&lt;String&gt;?&quot;"/>
-        </annotation>
-    </item>
-    <item name='java.io.File java.io.File[] listFiles()'>
-        <annotation name='jet.runtime.typeinfo.KotlinSignature'>
-            <val name="value" val="&quot;fun listFiles() : Array&lt;File&gt;?&quot;"/>
-        </annotation>
-    </item>
-    <item name='java.io.File java.io.File[] listFiles(java.io.FilenameFilter)'>
-        <annotation name='jet.runtime.typeinfo.KotlinSignature'>
-            <val name="value" val="&quot;fun listFiles(filter : FilenameFilter?) : Array&lt;File&gt;?&quot;"/>
-        </annotation>
-    </item>
-    <item name='java.io.File java.io.File[] listFiles(java.io.FileFilter)'>
-        <annotation name='jet.runtime.typeinfo.KotlinSignature'>
-            <val name="value" val="&quot;fun listFiles(filter : FileFilter?) : Array&lt;File&gt;?&quot;"/>
-        </annotation>
-    </item>
-    <item name='java.io.File boolean renameTo(java.io.File) 0'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.io.File[] listRoots()'>
-        <annotation name='jet.runtime.typeinfo.KotlinSignature'>
-            <val name="value" val="&quot;fun listRoots() : Array&lt;File&gt;?&quot;"/>
-        </annotation>
-    </item>
-    <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String, java.io.File) 0'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String, java.io.File) 1'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-    </item>
-    <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String, java.io.File) 2'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-    </item>
-    <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String, java.io.File)'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String) 0'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String) 1'>
-        <annotation name='org.jetbrains.annotations.Nullable'/>
-    </item>
-    <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String)'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.File java.lang.String toString()'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.FileFilter boolean accept(java.io.File) 0'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.FilenameFilter boolean accept(java.io.File, java.lang.String) 0'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
-    <item name='java.io.FilenameFilter boolean accept(java.io.File, java.lang.String) 1'>
-        <annotation name='org.jetbrains.annotations.NotNull'/>
-    </item>
+  <!-- java.io.File -->
+  <item name='java.io.File separator'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File pathSeparator'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File File(java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File File(java.lang.String, java.lang.String) 1'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File File(java.lang.String, java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.File File(java.io.File, java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.File File(java.io.File, java.lang.String) 1'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File File(java.net.URI) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.lang.String getName()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.lang.String getParent()'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.File java.io.File getParentFile()'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.File java.lang.String getPath()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.lang.String getAbsolutePath()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.io.File getAbsoluteFile()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.lang.String getCanonicalPath()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.io.File getCanonicalFile()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File @java.lang.Deprecated java.net.URL toURL()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.net.URI toURI()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.lang.String[] list()'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+    <annotation name='jet.runtime.typeinfo.KotlinSignature'>
+      <val name="value" val="&quot;fun list() : Array&lt;String&gt;?&quot;"/>
+    </annotation>
+  </item>
+  <item name='java.io.File java.lang.String[] list(java.io.FilenameFilter) 0'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.File java.lang.String[] list(java.io.FilenameFilter)'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+    <annotation name='jet.runtime.typeinfo.KotlinSignature'>
+      <val name="value" val="&quot;fun list(filter : FilenameFilter?) : Array&lt;String&gt;?&quot;"/>
+    </annotation>
+  </item>
+  <item name='java.io.File java.io.File[] listFiles()'>
+    <annotation name='jet.runtime.typeinfo.KotlinSignature'>
+      <val name="value" val="&quot;fun listFiles() : Array&lt;File&gt;?&quot;"/>
+    </annotation>
+  </item>
+  <item name='java.io.File java.io.File[] listFiles(java.io.FilenameFilter)'>
+    <annotation name='jet.runtime.typeinfo.KotlinSignature'>
+      <val name="value" val="&quot;fun listFiles(filter : FilenameFilter?) : Array&lt;File&gt;?&quot;"/>
+    </annotation>
+  </item>
+  <item name='java.io.File java.io.File[] listFiles(java.io.FileFilter)'>
+    <annotation name='jet.runtime.typeinfo.KotlinSignature'>
+      <val name="value" val="&quot;fun listFiles(filter : FileFilter?) : Array&lt;File&gt;?&quot;"/>
+    </annotation>
+  </item>
+  <item name='java.io.File boolean renameTo(java.io.File) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.io.File[] listRoots()'>
+    <annotation name='jet.runtime.typeinfo.KotlinSignature'>
+      <val name="value" val="&quot;fun listRoots() : Array&lt;File&gt;?&quot;"/>
+    </annotation>
+  </item>
+  <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String, java.io.File) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String, java.io.File) 1'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String, java.io.File) 2'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String, java.io.File)'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String) 1'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.File java.io.File createTempFile(java.lang.String, java.lang.String)'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.File java.lang.String toString()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.FileFilter -->
+  <item name='java.io.FileFilter boolean accept(java.io.File) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.FilenameFilter -->
+  <item name='java.io.FilenameFilter boolean accept(java.io.File, java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.FilenameFilter boolean accept(java.io.File, java.lang.String) 1'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.InputStream -->
+  <item name='java.io.InputStream int read(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.InputStream int read(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.OutputStream -->
+  <item name='java.io.OutputStream void write(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.OutputStream void write(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.FilterInputStream -->
+  <item name='java.io.FilterInputStream in'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.FilterInputStream FilterInputStream(java.io.InputStream) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.FilterInputStream int read(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.FilterInputStream int read(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.BufferedInputStream -->
+  <item name='java.io.BufferedInputStream buf'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.BufferedInputStream BufferedInputStream(java.io.InputStream) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.BufferedInputStream BufferedInputStream(java.io.InputStream, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.BufferedInputStream int read(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.ByteArrayInputStream -->
+  <item name='java.io.ByteArrayInputStream buf'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.ByteArrayInputStream ByteArrayInputStream(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.ByteArrayInputStream ByteArrayInputStream(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.ByteArrayInputStream int read(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.PushbackInputStream -->
+  <item name='java.io.PushbackInputStream buf'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.PushbackInputStream PushbackInputStream(java.io.InputStream, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.PushbackInputStream PushbackInputStream(java.io.InputStream) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.PushbackInputStream int read(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.PushbackInputStream void unread(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.PushbackInputStream void unread(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.BufferedOutputStream -->
+  <item name='java.io.BufferedOutputStream buf'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.BufferedOutputStream BufferedOutputStream(java.io.OutputStream) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.BufferedOutputStream BufferedOutputStream(java.io.OutputStream, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.FilterOutputStream -->
+  <item name='java.io.FilterOutputStream out'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.FilterOutputStream FilterOutputStream(java.io.OutputStream) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.FilterOutputStream void write(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.FilterOutputStream void write(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.BufferedOutputStream -->
+  <item name='java.io.BufferedOutputStream void write(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.ByteArrayOutputStream -->
+  <item name='java.io.ByteArrayOutputStream buf'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.ByteArrayOutputStream void write(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.ByteArrayOutputStream void writeTo(java.io.OutputStream) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.ByteArrayOutputStream byte[] toByteArray()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.ByteArrayOutputStream java.lang.String toString()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.ByteArrayOutputStream @java.lang.Deprecated java.lang.String toString(int)'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.DataOutput -->
+  <item name='java.io.DataOutput void write(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataOutput void write(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataOutput void writeUTF(java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.DataInput -->
+  <item name='java.io.DataInput void readFully(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInput void readFully(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInput java.lang.String readLine()'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.DataInput java.lang.String readUTF()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.DataInputStream -->
+  <item name='java.io.DataInputStream DataInputStream(java.io.InputStream) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInputStream int read(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInputStream int read(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInputStream void readFully(byte[]) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInputStream void readFully(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInputStream @java.lang.Deprecated java.lang.String readLine()'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='java.io.DataInputStream java.lang.String readUTF(java.io.DataInput) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInputStream java.lang.String readUTF(java.io.DataInput)'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataInputStream java.lang.String readUTF()'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <!-- java.io.DataOutputStream -->
+  <item name='java.io.DataOutputStream DataOutputStream(java.io.OutputStream) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataOutputStream void write(byte[], int, int) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataOutputStream void writeBytes(java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataOutputStream void writeChars(java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataOutputStream void writeUTF(java.lang.String) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataOutputStream int writeUTF(java.lang.String, java.io.DataOutput) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item name='java.io.DataOutputStream int writeUTF(java.lang.String, java.io.DataOutput) 1'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
 </root>
\ No newline at end of file
diff --git a/libraries/stdlib/src/kotlin/io/JIO.kt b/libraries/stdlib/src/kotlin/io/JIO.kt
index 8f3205f98fd..b800af03689 100644
--- a/libraries/stdlib/src/kotlin/io/JIO.kt
+++ b/libraries/stdlib/src/kotlin/io/JIO.kt
@@ -111,7 +111,7 @@ private val stdin : BufferedReader = BufferedReader(InputStreamReader(object : I
         System.`in`?.reset()
     }
 
-    public override fun read(b: ByteArray?): Int {
+    public override fun read(b: ByteArray): Int {
         return System.`in`?.read(b) ?: -1
     }
 
@@ -135,7 +135,7 @@ private val stdin : BufferedReader = BufferedReader(InputStreamReader(object : I
         return System.`in`?.markSupported() ?: false
     }
 
-    public override fun read(b: ByteArray?, off: Int, len: Int): Int {
+    public override fun read(b: ByteArray, off: Int, len: Int): Int {
         return System.`in`?.read(b, off, len) ?: -1
     }
 }))