diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java b/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java
index b3ee8b7f91d..716357da6b8 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/Errors.java
@@ -424,7 +424,7 @@ public interface Errors {
 
     // Control flow / Data flow
 
-    DiagnosticFactory0<JetElement> UNREACHABLE_CODE = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<JetElement> UNREACHABLE_CODE = DiagnosticFactory0.create(WARNING);
 
     DiagnosticFactory0<JetVariableDeclaration> VARIABLE_WITH_NO_TYPE_NO_INITIALIZER = DiagnosticFactory0.create(ERROR, NAME_IDENTIFIER);
 
diff --git a/idea/testData/checker/FunctionReturnTypes.kt b/idea/testData/checker/FunctionReturnTypes.kt
index 49e458a892a..f10d48a1d5d 100644
--- a/idea/testData/checker/FunctionReturnTypes.kt
+++ b/idea/testData/checker/FunctionReturnTypes.kt
@@ -48,7 +48,7 @@ fun blockAndAndMismatch1() : Int {
   return <error>true && false</error>
 }
 fun blockAndAndMismatch2() : Int {
-  <error>(return <error>true</error>) && (return <error>false</error>)</error>
+  <warning>(return <error>true</error>) && (return <error>false</error>)</warning>
 }
 
 fun blockAndAndMismatch3() : Int {
@@ -58,7 +58,7 @@ fun blockAndAndMismatch4() : Int {
   return <error>true || false</error>
 }
 fun blockAndAndMismatch5() : Int {
-  <error>(return <error>true</error>) || (return <error>false</error>)</error>
+  <warning>(return <error>true</error>) || (return <error>false</error>)</warning>
 }
 fun blockReturnValueTypeMatch1() : Int {
   return if (1 > 2) <error>1.0</error> else <error>2.0</error>
diff --git a/idea/testData/checker/UnreachableCode.kt b/idea/testData/checker/UnreachableCode.kt
index 08028200ed5..c8d87582541 100644
--- a/idea/testData/checker/UnreachableCode.kt
+++ b/idea/testData/checker/UnreachableCode.kt
@@ -1,79 +1,79 @@
 fun t1() : Int{
   return 0
-  <error>1</error>
+  <warning>1</warning>
 }
 
 fun t1a() : Int {
   <error>return</error>
-  <error>return 1</error>
-  <error>1</error>
+  <warning>return 1</warning>
+  <warning>1</warning>
 }
 
 fun t1b() : Int {
   return 1
-  <error>return 1</error>
-  <error>1</error>
+  <warning>return 1</warning>
+  <warning>1</warning>
 }
 
 fun t1c() : Int {
   return 1
   <error>return</error>
-  <error>1</error>
+  <warning>1</warning>
 }
 
 fun t2() : Int {
   if (1 > 2)
     return 1
   else return 1
-  <error>1</error>
+  <warning>1</warning>
 }
 
 fun t2a() : Int {
   if (1 > 2) {
     return 1
-    <error>1</error>
+    <warning>1</warning>
   } else { return 1
-    <error>2</error>
+    <warning>2</warning>
   }
-  <error>1</error>
+  <warning>1</warning>
 }
 
 fun t3() : Any {
   if (1 > 2)
     return 2
   else return ""
-  <error>1</error>
+  <warning>1</warning>
 }
 
 fun t4(<warning>a</warning> : Boolean) : Int {
   do {
     return 1
   }
-  while (<error>a</error>)
-  <error>1</error>
+  while (<warning>a</warning>)
+  <warning>1</warning>
 }
 
 fun t4break(<warning>a</warning> : Boolean) : Int {
   do {
     break
   }
-  while (<error>a</error>)
+  while (<warning>a</warning>)
   return 1
 }
 
 fun t5() : Int {
   do {
     return 1
-    <error>2</error>
+    <warning>2</warning>
   }
-  while (<error>1 > 2</error>)
-  <error>return 1</error>
+  while (<warning>1 > 2</warning>)
+  <warning>return 1</warning>
 }
 
 fun t6() : Int {
   while (1 > 2) {
     return 1
-    <error>2</error>
+    <warning>2</warning>
   }
   return 1
 }
@@ -81,7 +81,7 @@ fun t6() : Int {
 fun t6break() : Int {
   while (1 > 2) {
     break
-    <error>2</error>
+    <warning>2</warning>
   }
   return 1
 }
@@ -89,7 +89,7 @@ fun t6break() : Int {
 fun t7(b : Int) : Int {
   for (i in 1..b) {
     return 1
-    <error>2</error>
+    <warning>2</warning>
   }
   return 1
 }
@@ -97,7 +97,7 @@ fun t7(b : Int) : Int {
 fun t7break(b : Int) : Int {
   for (i in 1..b) {
     return 1
-    <error>2</error>
+    <warning>2</warning>
   }
   return 1
 }
@@ -105,7 +105,7 @@ fun t7break(b : Int) : Int {
 fun t7() : Int {
   try {
     return 1
-    <error>2</error>
+    <warning>2</warning>
   }
   catch (<error>e : Any</error>) {
     <warning>2</warning>
@@ -116,36 +116,36 @@ fun t7() : Int {
 fun t8() : Int {
   try {
     return 1
-    <error>2</error>
+    <warning>2</warning>
   }
   catch (<error>e : Any</error>) {
     return 1
-    <error>2</error>
+    <warning>2</warning>
   }
-  <error>return 1</error>
+  <warning>return 1</warning>
 }
 
 fun blockAndAndMismatch() : Boolean {
-  <error>(return true) || (return false)</error>
-  <error>return true</error>
+  <warning>(return true) || (return false)</warning>
+  <warning>return true</warning>
 }
 
 fun tf() : Int {
-  try {<error>return 1</error>} finally{return 1}
-  <error>return 1</error>
+  try {<warning>return 1</warning>} finally{return 1}
+  <warning>return 1</warning>
 }
 
 fun failtest(<warning>a</warning> : Int) : Int {
-  if (fail() || <error>true</error>) {
+  if (fail() || <warning>true</warning>) {
 
   }
-  <error>return 1</error>
+  <warning>return 1</warning>
 }
 
 fun foo(a : Nothing) : Unit {
   <warning>1</warning>
   <warning>a</warning>
-  <error>2</error>
+  <warning>2</warning>
 }
 
 fun fail() : Nothing {
diff --git a/idea/testData/checker/When.kt b/idea/testData/checker/When.kt
index 33bf192ed99..7b7afdebfc3 100644
--- a/idea/testData/checker/When.kt
+++ b/idea/testData/checker/When.kt
@@ -36,7 +36,7 @@ fun test() {
 
   when (z) {
     <error>else</error> -> 1
-    <error>1 -> 2</error>
+    <warning>1 -> 2</warning>
   }
 
   when (z) {
diff --git a/idea/testData/quickfix/when/beforeTwoElseBranchesInWhen.kt b/idea/testData/quickfix/when/beforeTwoElseBranchesInWhen.kt
index 4525fbfd3f1..6ff3c7d7e1e 100644
--- a/idea/testData/quickfix/when/beforeTwoElseBranchesInWhen.kt
+++ b/idea/testData/quickfix/when/beforeTwoElseBranchesInWhen.kt
@@ -1,8 +1,8 @@
 // "Move else branch to the end" "false"
 // ERROR: 'else' entry must be the last one in a when-expression
 // ERROR: 'else' entry must be the last one in a when-expression
-// ERROR: Unreachable code
-// ERROR: Unreachable code
+// WARNING: Unreachable code
+// WARNING: Unreachable code
 // ACTION: Disable 'Eliminate Argument of 'when''
 // ACTION: Disable 'Replace 'when' with 'if''
 // ACTION: Edit intention settings