diff --git a/compiler/testData/diagnostics/testsWithStdLib/contracts/fromStdlib/check.kt b/compiler/testData/diagnostics/testsWithStdLib/contracts/fromStdlib/check.kt
index 873062fc774..df534621847 100644
--- a/compiler/testData/diagnostics/testsWithStdLib/contracts/fromStdlib/check.kt
+++ b/compiler/testData/diagnostics/testsWithStdLib/contracts/fromStdlib/check.kt
@@ -22,7 +22,12 @@ fun testCheckWithFailingMessage(x: Any?) {
     <!DEBUG_INFO_SMARTCAST!>x<!>.length
 }
 
-fun tesCheckNotNullWithMessage(x: Int?) {
-    checkNotNull(x) { "x is null!"}
+fun testCheckNotNullWithMessage(x: Int?) {
+    checkNotNull(x) { "x is null!" }
+    <!DEBUG_INFO_SMARTCAST!>x<!>.inc()
+}
+
+fun testCheckNotNull(x: Int?) {
+    checkNotNull(x)
     <!DEBUG_INFO_SMARTCAST!>x<!>.inc()
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithStdLib/contracts/fromStdlib/check.txt b/compiler/testData/diagnostics/testsWithStdLib/contracts/fromStdlib/check.txt
index e62fe7822c1..b102d8eb8f4 100644
--- a/compiler/testData/diagnostics/testsWithStdLib/contracts/fromStdlib/check.txt
+++ b/compiler/testData/diagnostics/testsWithStdLib/contracts/fromStdlib/check.txt
@@ -1,6 +1,7 @@
 package
 
-public fun tesCheckNotNullWithMessage(/*0*/ x: kotlin.Int?): kotlin.Unit
+public fun testCheckNotNull(/*0*/ x: kotlin.Int?): kotlin.Unit
+public fun testCheckNotNullWithMessage(/*0*/ x: kotlin.Int?): kotlin.Unit
 public fun testCheckSmartcast(/*0*/ x: kotlin.Any?): kotlin.Unit
 public fun testCheckUnreachableCode(): kotlin.Unit
 public fun testCheckWithFailingMessage(/*0*/ x: kotlin.Any?): kotlin.Unit
diff --git a/libraries/stdlib/src/kotlin/util/Preconditions.kt b/libraries/stdlib/src/kotlin/util/Preconditions.kt
index 97511d75f78..7f87628b38d 100644
--- a/libraries/stdlib/src/kotlin/util/Preconditions.kt
+++ b/libraries/stdlib/src/kotlin/util/Preconditions.kt
@@ -106,7 +106,12 @@ public inline fun check(value: Boolean, lazyMessage: () -> Any): Unit {
  * @sample samples.misc.Preconditions.failCheckWithLazyMessage
  */
 @kotlin.internal.InlineOnly
-public inline fun <T : Any> checkNotNull(value: T?): T = checkNotNull(value) { "Required value was null." }
+public inline fun <T : Any> checkNotNull(value: T?): T {
+    contract {
+        returns() implies (value != null)
+    }
+    return checkNotNull(value) { "Required value was null." }
+}
 
 /**
  * Throws an [IllegalStateException] with the result of calling [lazyMessage]  if the [value] is null. Otherwise