diff --git a/libraries/stdlib/src/kotlin/Arrays.kt b/libraries/stdlib/src/kotlin/Arrays.kt
index 15f4e031e92..677d8735d3f 100644
--- a/libraries/stdlib/src/kotlin/Arrays.kt
+++ b/libraries/stdlib/src/kotlin/Arrays.kt
@@ -88,6 +88,7 @@ public inline fun   FloatArray.copyOf(newLength: Int = this.size) : FloatArray
 public inline fun  DoubleArray.copyOf(newLength: Int = this.size) : DoubleArray  = Arrays.copyOf(this, newLength).sure()
 public inline fun    CharArray.copyOf(newLength: Int = this.size) : CharArray    = Arrays.copyOf(this, newLength).sure()
 
+// TODO: resuling array may contain nulls even if T is non-nullable
 public inline fun  <T> Array<T>.copyOf(newLength: Int = this.size) : Array<T> = Arrays.copyOf(this as Array<T?>, newLength) as Array<T>
 
 public inline fun BooleanArray.copyOfRange(from: Int, to: Int) : BooleanArray = Arrays.copyOfRange(this, from, to).sure()
@@ -99,6 +100,7 @@ public inline fun   FloatArray.copyOfRange(from: Int, to: Int) : FloatArray   =
 public inline fun  DoubleArray.copyOfRange(from: Int, to: Int) : DoubleArray  = Arrays.copyOfRange(this, from, to).sure()
 public inline fun    CharArray.copyOfRange(from: Int, to: Int) : CharArray    = Arrays.copyOfRange(this, from, to).sure()
 
+// TODO: resuling array may contain nulls even if T is non-nullable
 public inline fun  <T> Array<T>.copyOfRange(from: Int, to: Int) : Array<T> = Arrays.copyOfRange(this as Array<T?>, from, to) as Array<T>
 
 public inline val ByteArray.inputStream : ByteArrayInputStream