diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java b/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
index 9c72de95925..f47afb4ae47 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
@@ -2088,6 +2088,22 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
 
     @Override
     public StackValue visitPostfixExpression(JetPostfixExpression expression, StackValue receiver) {
+        if(expression.getOperationReference().getReferencedNameElementType() == JetTokens.EXCLEXCL) {
+            JetExpression baseExpression = expression.getBaseExpression();
+            JetType type = bindingContext.get(BindingContext.EXPRESSION_TYPE, baseExpression);
+            StackValue base = genQualified(receiver, baseExpression);
+            if(type != null && type.isNullable()) {
+                base.put(base.type, v);
+                v.dup();
+                Label ok = new Label();
+                v.ifnonnull(ok);
+                v.invokestatic("jet/runtime/Intrinsics", "throwNpe", "()V");
+                v.mark(ok);
+                return StackValue.onStack(base.type);
+            }
+            else 
+                return base;
+        }
         DeclarationDescriptor op = bindingContext.get(BindingContext.REFERENCE_TARGET, expression.getOperationReference());
         if (op instanceof FunctionDescriptor) {
             final Type asmType = expressionType(expression);
@@ -2153,7 +2169,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
                 }
             }
         }
-        throw new UnsupportedOperationException("Don't know how to generate this prefix expression");
+        throw new UnsupportedOperationException("Don't know how to generate this postfix expression");
     }
 
     private void generateIncrement(DeclarationDescriptor op, Type asmType, JetExpression operand, StackValue receiver) {
diff --git a/compiler/testData/codegen/regressions/kt628.kt b/compiler/testData/codegen/regressions/kt628.kt
new file mode 100644
index 00000000000..32ff6d416f8
--- /dev/null
+++ b/compiler/testData/codegen/regressions/kt628.kt
@@ -0,0 +1,48 @@
+class A() {
+  fun action() = "OK"
+
+  fun infix(a: String) = "O" + a
+
+  val property = "OK"
+
+  val a : A
+    get() = A()
+}
+
+fun test1()  = A()!!.property
+fun test2()  = (A() as A?)!!.property
+fun test3()  = A()!!.action()
+fun test4()  = (A() as A?)!!.action()
+fun test5()  = (null as A?)!!.action()
+fun test6()  = A().a.a!!.action()
+fun test7()  = 10!!.plus(11)
+fun test8()  = (10 as Int?)!!.plus(11)
+fun test9()  = A()!! infix "K"
+fun test10() = (A() as A?) !! infix "K"
+fun test11() = (A() as A?) !! infix("K")
+fun test12()  = A()!! infix ("K")
+
+fun box() : String {
+  if(test1() != "OK") return "fail"
+  if(test2() != "OK") return "fail"
+  if(test3() != "OK") return "fail"
+  if(test4() != "OK") return "fail"
+
+  try {
+      test5()
+      return "fail"
+  }
+  catch(e: NullPointerException) { //
+  }
+
+  if(test6() != "OK") return "fail"
+  if(test7() != 21) return "fail"
+  if(test8() != 21) return "fail"
+
+  if(test9() != "OK") return "fail"
+  if(test10() != "OK") return "fail"
+  if(test11() != "OK") return "fail"
+  if(test12() != "OK") return "fail"
+
+  return "OK"
+}
\ No newline at end of file
diff --git a/compiler/tests/org/jetbrains/jet/codegen/ControlStructuresTest.java b/compiler/tests/org/jetbrains/jet/codegen/ControlStructuresTest.java
index ece95738d98..c77fc11498b 100644
--- a/compiler/tests/org/jetbrains/jet/codegen/ControlStructuresTest.java
+++ b/compiler/tests/org/jetbrains/jet/codegen/ControlStructuresTest.java
@@ -286,4 +286,8 @@ public class ControlStructuresTest extends CodegenTestCase {
     public void testKt998() throws Exception {
         blackBoxFile("regressions/kt998.kt");
     }
+
+    public void testKt628() throws Exception {
+        blackBoxFile("regressions/kt628.kt");
+    }
 }