diff --git a/compiler/frontend/src/org/jetbrains/jet/checkers/CheckerTestUtil.java b/compiler/frontend/src/org/jetbrains/jet/checkers/CheckerTestUtil.java
index 1ea243434dd..c364fa0b31f 100644
--- a/compiler/frontend/src/org/jetbrains/jet/checkers/CheckerTestUtil.java
+++ b/compiler/frontend/src/org/jetbrains/jet/checkers/CheckerTestUtil.java
@@ -23,6 +23,7 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiErrorElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.util.Function;
 import com.intellij.util.containers.Stack;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.diagnostics.Diagnostic;
@@ -32,7 +33,6 @@ import org.jetbrains.jet.lang.psi.JetExpression;
 import org.jetbrains.jet.lang.psi.JetReferenceExpression;
 import org.jetbrains.jet.lang.resolve.AnalyzingUtils;
 import org.jetbrains.jet.lang.resolve.BindingContext;
-import org.jetbrains.jet.lang.types.JetType;
 
 import java.util.*;
 import java.util.regex.Matcher;
@@ -255,9 +255,22 @@ public class CheckerTestUtil {
         return matcher.replaceAll("");
     }
     
-    public static StringBuffer addDiagnosticMarkersToText(@NotNull final PsiFile psiFile, Collection<Diagnostic> diagnostics) {
+    public static StringBuffer addDiagnosticMarkersToText(@NotNull final PsiFile psiFile, @NotNull Collection<Diagnostic> diagnostics) {
+        return addDiagnosticMarkersToText(psiFile, diagnostics, new Function<PsiFile, String>() {
+            @Override
+            public String fun(PsiFile file) {
+                return file.getText();
+            }
+        });
+    }
+
+    public static StringBuffer addDiagnosticMarkersToText(
+            @NotNull final PsiFile psiFile,
+            @NotNull Collection<Diagnostic> diagnostics,
+            @NotNull Function<PsiFile, String> getFileText
+    ) {
+        String text = getFileText.fun(psiFile);
         StringBuffer result = new StringBuffer();
-        String text = psiFile.getText();
         diagnostics = Collections2.filter(diagnostics, new Predicate<Diagnostic>() {
             @Override
             public boolean apply(Diagnostic diagnostic) {
diff --git a/compiler/testData/diagnostics/tests/checkType.kt b/compiler/testData/diagnostics/tests/checkType.kt
new file mode 100644
index 00000000000..e9dc7d6ce1e
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/checkType.kt
@@ -0,0 +1,11 @@
+// !CHECK_TYPE
+
+trait A
+trait B : A
+trait C : B
+
+fun test(b: B) {
+    b checkType { it : _<B> }
+    b checkType { <!TYPE_MISMATCH!>it<!> : _<A> }
+    b checkType { <!TYPE_MISMATCH!>it<!> : _<C> }
+}
diff --git a/compiler/testData/diagnostics/tests/functionLiterals/functionLIteralInBlockInIf.kt b/compiler/testData/diagnostics/tests/functionLiterals/functionLIteralInBlockInIf.kt
index 4133a0318bb..c658d0c01e3 100644
--- a/compiler/testData/diagnostics/tests/functionLiterals/functionLIteralInBlockInIf.kt
+++ b/compiler/testData/diagnostics/tests/functionLiterals/functionLIteralInBlockInIf.kt
@@ -1,3 +1,4 @@
+// !CHECK_TYPE
 fun test() {
     val a = if (true) {
         val x = 1
@@ -5,7 +6,5 @@ fun test() {
     } else {
         { 2 }
     }
-    TypeOf(a): TypeOf<Function0<Int>>
-}
-
-class TypeOf<T>(t: T)
\ No newline at end of file
+    a checkType { it : _<() -> Int> }
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/functionLiterals/functionLiteralWithoutArgumentList.kt b/compiler/testData/diagnostics/tests/functionLiterals/functionLiteralWithoutArgumentList.kt
index ed84584db2b..78190d17a22 100644
--- a/compiler/testData/diagnostics/tests/functionLiterals/functionLiteralWithoutArgumentList.kt
+++ b/compiler/testData/diagnostics/tests/functionLiterals/functionLiteralWithoutArgumentList.kt
@@ -1,8 +1,7 @@
-class TypeOf<T>(t: T)
-
+// !CHECK_TYPE
 fun <T> id(t: T) = t
 
 fun foo() {
     val i = id { 22 } //type inference error: no information for parameter
-    TypeOf(i): TypeOf<()->Int>
+    i checkType { it : _<()->Int> }
 }
diff --git a/compiler/testData/diagnostics/tests/generics/varProjection/setterNotProjectedOutAssign.kt b/compiler/testData/diagnostics/tests/generics/varProjection/setterNotProjectedOutAssign.kt
index e082d821eb4..4aa9cad51af 100644
--- a/compiler/testData/diagnostics/tests/generics/varProjection/setterNotProjectedOutAssign.kt
+++ b/compiler/testData/diagnostics/tests/generics/varProjection/setterNotProjectedOutAssign.kt
@@ -1,11 +1,9 @@
+// !CHECK_TYPE
 trait Tr<T> {
     var v: Tr<T>
 }
 
 fun test(t: Tr<*>) {
     t.v = t
-    val v = TypeOf(t.v)
-    v: TypeOf<Tr<*>>
-}
-
-class TypeOf<T>(t: T)
\ No newline at end of file
+    t.v checkType { it : _<Tr<*>> }
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/generics/varProjection/setterProjectedOutAssign.kt b/compiler/testData/diagnostics/tests/generics/varProjection/setterProjectedOutAssign.kt
index 8fc8a74ae62..5396cc7c331 100644
--- a/compiler/testData/diagnostics/tests/generics/varProjection/setterProjectedOutAssign.kt
+++ b/compiler/testData/diagnostics/tests/generics/varProjection/setterProjectedOutAssign.kt
@@ -1,4 +1,5 @@
 // !DIAGNOSTICS: -UNREACHABLE_CODE -UNUSED_PARAMETER
+// !CHECK_TYPE
 // t is unused due to KT-4233
 trait Tr<T> {
     var v: T
@@ -6,8 +7,5 @@ trait Tr<T> {
 
 fun test(t: Tr<*>) {
     <!SETTER_PROJECTED_OUT!>t.v<!> = null!!
-    val v = TypeOf(t.v)
-    v: TypeOf<Any?>
-}
-
-class TypeOf<T>(t: T)
\ No newline at end of file
+    t.v checkType { it : _<Any?> }
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/inference/constraints/equalityConstraintOnNullableType.kt b/compiler/testData/diagnostics/tests/inference/constraints/equalityConstraintOnNullableType.kt
index 4454c3f8fde..b458c7e80a9 100644
--- a/compiler/testData/diagnostics/tests/inference/constraints/equalityConstraintOnNullableType.kt
+++ b/compiler/testData/diagnostics/tests/inference/constraints/equalityConstraintOnNullableType.kt
@@ -1,6 +1,5 @@
 // !DIAGNOSTICS: -BASE_WITH_NULLABLE_UPPER_BOUND
-class TypeOf<T>(t: T)
-
+// !CHECK_TYPE
 trait A<T>
 
 fun <T> foo(a: A<T>, aN: A<T?>): T = throw Exception("$a $aN")
@@ -9,13 +8,13 @@ fun <T> doA(a: A<T>): T = throw Exception("$a")
 
 fun test(a: A<Int>, aN: A<Int?>) {
     val aa = doA(aN)
-    TypeOf(aa): TypeOf<Int?>
+    aa checkType { it : _<Int?> }
 
     val nullable = foo(aN, aN)
     //T = Int?, T? = Int? => T = Int?
-    TypeOf(nullable): TypeOf<Int?>
+    nullable checkType { it : _<Int?> }
 
     val notNullable = foo(a, aN)
     //T = Int, T? = Int? => T = Int
-    TypeOf(notNullable): TypeOf<Int>
+    notNullable checkType { it : _<Int> }
 }
diff --git a/compiler/testData/diagnostics/tests/inference/constraints/notNullConstraintOnNullableType.kt b/compiler/testData/diagnostics/tests/inference/constraints/notNullConstraintOnNullableType.kt
index af4c22b6ca5..4691a4e3e27 100644
--- a/compiler/testData/diagnostics/tests/inference/constraints/notNullConstraintOnNullableType.kt
+++ b/compiler/testData/diagnostics/tests/inference/constraints/notNullConstraintOnNullableType.kt
@@ -1,5 +1,4 @@
-class TypeOf<T>(t: T)
-
+// !CHECK_TYPE
 trait A<T>
 
 trait In<in T>
@@ -15,7 +14,7 @@ fun test(out: Out<Int>, i: In<Int>, inv: A<Int>) {
     // T? >: Int => T = Int
     doT(1)
     val r = doOut(out)
-    TypeOf(r): TypeOf<Int>
+    r checkType { it : _<Int> }
 
     // T? <: Int => error
     doIn(<!TYPE_MISMATCH!>i<!>)
diff --git a/compiler/testData/diagnostics/tests/inference/constraints/subtypeConstraintOnNullableType.kt b/compiler/testData/diagnostics/tests/inference/constraints/subtypeConstraintOnNullableType.kt
index de1d49a45eb..1f12fd4ba8a 100644
--- a/compiler/testData/diagnostics/tests/inference/constraints/subtypeConstraintOnNullableType.kt
+++ b/compiler/testData/diagnostics/tests/inference/constraints/subtypeConstraintOnNullableType.kt
@@ -1,6 +1,5 @@
 // !DIAGNOSTICS: -BASE_WITH_NULLABLE_UPPER_BOUND
-class TypeOf<T>(t: T)
-
+// !CHECK_TYPE
 trait A<T>
 
 trait Out<out T>
@@ -12,13 +11,13 @@ fun <T> doOut(o: Out<T?>): T = throw Exception("$o")
 fun test(a: A<Int>, aN: A<Int?>, o: Out<Int?>) {
     val out = doOut(o)
     //T? >: Int? => T >: Int
-    TypeOf(out): TypeOf<Int>
+    out checkType { it : _<Int> }
 
     val nullable = foo(aN, o)
     //T = Int?, T? >: Int? => T = Int?
-    TypeOf(nullable): TypeOf<Int?>
+    nullable checkType { it : _<Int?> }
 
     val notNullable = foo(a, o)
     //T = Int, T? >: Int? => T = Int
-    TypeOf(notNullable): TypeOf<Int>
+    notNullable checkType { it : _<Int> }
 }
diff --git a/compiler/testData/diagnostics/tests/inference/constraints/supertypeConstraintOnNullableType.kt b/compiler/testData/diagnostics/tests/inference/constraints/supertypeConstraintOnNullableType.kt
index 9aacaca6268..982f67e8f6d 100644
--- a/compiler/testData/diagnostics/tests/inference/constraints/supertypeConstraintOnNullableType.kt
+++ b/compiler/testData/diagnostics/tests/inference/constraints/supertypeConstraintOnNullableType.kt
@@ -1,6 +1,5 @@
 // !DIAGNOSTICS: -BASE_WITH_NULLABLE_UPPER_BOUND
-class TypeOf<T>(t: T)
-
+// !CHECK_TYPE
 trait A<T>
 
 trait In<in T>
@@ -12,13 +11,13 @@ fun <T> doIn(i: In<T?>): T = throw Exception("$i")
 fun test(a: A<Int>, aN: A<Int?>, i: In<Int?>) {
     val _in = doIn(i)
     //T? <: Int? => T <: Int?
-    TypeOf(_in): TypeOf<Int?>
+    _in checkType { it : _<Int?> }
 
     val notNullable = foo(a, i)
     //T = Int, T? <: Int? => T = Int
-    TypeOf(notNullable): TypeOf<Int>
+    notNullable checkType { it : _<Int> }
 
     val nullable = foo(aN, i)
     //T = Int?, T? <: Int? => T = Int?
-    TypeOf(nullable): TypeOf<Int?>
+    nullable checkType { it : _<Int?> }
 }
diff --git a/compiler/testData/diagnostics/tests/numbers/numbersInSimpleConstraints.kt b/compiler/testData/diagnostics/tests/numbers/numbersInSimpleConstraints.kt
index 5f5f9585445..be29bca7ba2 100644
--- a/compiler/testData/diagnostics/tests/numbers/numbersInSimpleConstraints.kt
+++ b/compiler/testData/diagnostics/tests/numbers/numbersInSimpleConstraints.kt
@@ -1,7 +1,6 @@
+// !CHECK_TYPE
 package a
 
-class TypeOf<T>(t: T)
-
 fun <T> id(t: T): T = t
 
 fun <T> either(t1: T, <!UNUSED_PARAMETER!>t2<!>: T): T = t1
@@ -21,7 +20,7 @@ fun test() {
     d: Int
 
     val e = id(9223372036854775807)
-    TypeOf(e): TypeOf<Long>
+    e checkType { it : _<Long> }
 
     val f: Byte = either(1, 2)
 
@@ -32,7 +31,7 @@ fun test() {
     <!TYPE_INFERENCE_TYPE_CONSTRUCTOR_MISMATCH!>otherGeneric<!>(<!CONSTANT_EXPECTED_TYPE_MISMATCH!>1<!>)
 
     val r = either(1, "")
-    TypeOf(r): TypeOf<Any>
+    r checkType { it : _<Comparable<*>> }
 
     use(a, b, c, d, e, f, g, r)
 }
@@ -48,7 +47,7 @@ fun testExactBound(invS: Inv<String>, invI: Inv<Int>, invB: Inv<Byte>) {
     exactBound(1, invI)
 
     val b = exactBound(1, invB)
-    TypeOf(b): TypeOf<Byte>
+    b checkType { it : _<Byte> }
 }
 
 trait Cov<out T>
@@ -57,10 +56,10 @@ fun <T> lowerBound(t: T, l : Cov<T>): T = throw Exception("$t $l")
 
 fun testLowerBound(cov: Cov<String>, covN: Cov<Number>) {
     val r = lowerBound(1, cov)
-    TypeOf(r): TypeOf<Any>
+    r checkType { it : _<Comparable<*>> }
 
     val n = lowerBound(1, covN)
-    TypeOf(n): TypeOf<Number>
+    n checkType { it : _<Number> }
 }
 
 trait Contr<in T>
@@ -71,8 +70,8 @@ fun testUpperBound(contrS: Contr<String>, contrB: Contr<Byte>, contrN: Contr<Num
     <!TYPE_INFERENCE_CONFLICTING_SUBSTITUTIONS!>upperBound<!>(1, contrS)
 
     val n = upperBound(1, contrN)
-    TypeOf(n): TypeOf<Int>
+    n checkType { it : _<Int> }
 
     val b = upperBound(1, contrB)
-    TypeOf(b): TypeOf<Byte>
+    b checkType { it : _<Byte> }
 }
diff --git a/compiler/tests/org/jetbrains/jet/JetTestUtils.java b/compiler/tests/org/jetbrains/jet/JetTestUtils.java
index 130a33ccc6c..f3e0c9e318e 100644
--- a/compiler/tests/org/jetbrains/jet/JetTestUtils.java
+++ b/compiler/tests/org/jetbrains/jet/JetTestUtils.java
@@ -87,10 +87,10 @@ import static org.jetbrains.jet.cli.jvm.JVMConfigurationKeys.CLASSPATH_KEY;
 
 public class JetTestUtils {
     private static final Pattern KT_FILES = Pattern.compile(".*?.kt");
-    private static List<File> filesToDelete = new ArrayList<File>();
+    private static final List<File> filesToDelete = new ArrayList<File>();
 
     public static final Pattern FILE_PATTERN = Pattern.compile("//\\s*FILE:\\s*(.*)$", Pattern.MULTILINE);
-    public static final Pattern DIRECTIVE_PATTERN = Pattern.compile("^//\\s*!(\\w+):\\s*(.*)$", Pattern.MULTILINE);
+    public static final Pattern DIRECTIVE_PATTERN = Pattern.compile("^//\\s*!(\\w+)(:\\s*(.*)$)?", Pattern.MULTILINE);
 
     public static final BindingTrace DUMMY_TRACE = new BindingTrace() {
 
@@ -453,7 +453,7 @@ public class JetTestUtils {
                 Assert.fail("Directives should only occur at the beginning of a file: " + directiveMatcher.group());
             }
             String name = directiveMatcher.group(1);
-            String value = directiveMatcher.group(2);
+            String value = directiveMatcher.group(3);
             String oldValue = directives.put(name, value);
             Assert.assertNull("Directive overwritten: " + name + " old value: " + oldValue + " new value: " + value, oldValue);
             start = directiveMatcher.end() + 1;
diff --git a/compiler/tests/org/jetbrains/jet/checkers/AbstractJetDiagnosticsTest.java b/compiler/tests/org/jetbrains/jet/checkers/AbstractJetDiagnosticsTest.java
index c42c3ca6d64..6baa5a3a866 100644
--- a/compiler/tests/org/jetbrains/jet/checkers/AbstractJetDiagnosticsTest.java
+++ b/compiler/tests/org/jetbrains/jet/checkers/AbstractJetDiagnosticsTest.java
@@ -24,7 +24,10 @@ import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.util.Conditions;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.io.FileUtil;
+import com.intellij.openapi.util.text.StringUtil;
+import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiFileFactory;
+import com.intellij.util.Function;
 import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -61,6 +64,9 @@ public abstract class AbstractJetDiagnosticsTest extends JetLiteFixture {
                     CheckerTestUtil.DebugInfoDiagnosticFactory.MISSING_UNRESOLVED,
                     CheckerTestUtil.DebugInfoDiagnosticFactory.UNRESOLVED_WITH_TARGET
             );
+    public static final String CHECK_TYPE_DIRECTIVE = "CHECK_TYPE";
+    private static final String CHECK_TYPE_DECLARATIONS = "\nclass _<T>" +
+                                                          "\nfun <T> T.checkType(f: (_<T>) -> Unit) = f";
 
     @Override
     protected JetCoreEnvironment createEnvironment() {
@@ -103,7 +109,7 @@ public abstract class AbstractJetDiagnosticsTest extends JetLiteFixture {
                         if (fileName.endsWith(".java")) {
                             writeJavaFile(fileName, text, javaFilesDir);
                         }
-                        return new TestFile(fileName, text, parseDiagnosticFilterDirective(directives));
+                        return new TestFile(fileName, text, directives);
                     }
                 });
 
@@ -125,8 +131,8 @@ public abstract class AbstractJetDiagnosticsTest extends JetLiteFixture {
         return jetFiles;
     }
 
-    public static Condition<Diagnostic> parseDiagnosticFilterDirective(Map<String, String> diagnostics) {
-        String directives = diagnostics.get(DIAGNOSTICS_DIRECTIVE);
+    public static Condition<Diagnostic> parseDiagnosticFilterDirective(Map<String, String> directiveMap) {
+        String directives = directiveMap.get(DIAGNOSTICS_DIRECTIVE);
         if (directives == null) {
             return Conditions.alwaysTrue();
         }
@@ -197,9 +203,15 @@ public abstract class AbstractJetDiagnosticsTest extends JetLiteFixture {
         private final String clearText;
         private final JetFile jetFile;
         private final Condition<Diagnostic> whatDiagnosticsToConsider;
+        private final boolean declareCheckType;
 
-        public TestFile(String fileName, String textWithMarkers, Condition<Diagnostic> whatDiagnosticsToConsider) {
-            this.whatDiagnosticsToConsider = whatDiagnosticsToConsider;
+        public TestFile(
+                String fileName,
+                String textWithMarkers,
+                Map<String, String> directives
+        ) {
+            this.whatDiagnosticsToConsider = parseDiagnosticFilterDirective(directives);
+            this.declareCheckType = directives.containsKey(CHECK_TYPE_DIRECTIVE);
             if (fileName.endsWith(".java")) {
                 PsiFileFactory.getInstance(getProject()).createFileFromText(fileName, JavaLanguage.INSTANCE, textWithMarkers);
                 // TODO: check there's not syntax errors
@@ -209,13 +221,15 @@ public abstract class AbstractJetDiagnosticsTest extends JetLiteFixture {
             else {
                 expectedText = textWithMarkers;
                 clearText = CheckerTestUtil.parseDiagnosedRanges(expectedText, diagnosedRanges);
-                this.jetFile = createCheckAndReturnPsiFile(null, fileName, clearText);
+                this.jetFile = createCheckAndReturnPsiFile(
+                        null, fileName, declareCheckType ? clearText + CHECK_TYPE_DECLARATIONS : clearText);
                 for (CheckerTestUtil.DiagnosedRange diagnosedRange : diagnosedRanges) {
                     diagnosedRange.setFile(jetFile);
                 }
             }
         }
 
+
         @Nullable
         public JetFile getJetFile() {
             return jetFile;
@@ -250,10 +264,14 @@ public abstract class AbstractJetDiagnosticsTest extends JetLiteFixture {
                 }
             });
 
-            actualText.append(CheckerTestUtil.addDiagnosticMarkersToText(jetFile, diagnostics));
+            actualText.append(CheckerTestUtil.addDiagnosticMarkersToText(jetFile, diagnostics, new Function<PsiFile, String>() {
+                @Override
+                public String fun(PsiFile file) {
+                    String text = file.getText();
+                    return declareCheckType ? StringUtil.trimEnd(text, CHECK_TYPE_DECLARATIONS) : text;
+                }
+            }));
             return ok[0];
         }
-
     }
-
 }
diff --git a/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
index ed47a6cb699..66ce350fd41 100644
--- a/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
@@ -119,6 +119,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
             doTest("compiler/testData/diagnostics/tests/CharacterLiterals.kt");
         }
         
+        @TestMetadata("checkType.kt")
+        public void testCheckType() throws Exception {
+            doTest("compiler/testData/diagnostics/tests/checkType.kt");
+        }
+        
         @TestMetadata("CompareToWithErrorType.kt")
         public void testCompareToWithErrorType() throws Exception {
             doTest("compiler/testData/diagnostics/tests/CompareToWithErrorType.kt");