diff --git a/core/builtins/builtins.iml b/core/builtins/builtins.iml
index a0b1f9f1895..72aeb571869 100644
--- a/core/builtins/builtins.iml
+++ b/core/builtins/builtins.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/core/descriptor.loader.java/descriptor.loader.java.iml b/core/descriptor.loader.java/descriptor.loader.java.iml
index a8a8a766e01..94131c24920 100644
--- a/core/descriptor.loader.java/descriptor.loader.java.iml
+++ b/core/descriptor.loader.java/descriptor.loader.java.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/core/descriptors.runtime/descriptors.runtime.iml b/core/descriptors.runtime/descriptors.runtime.iml
index 80978078587..5db6af1d4aa 100644
--- a/core/descriptors.runtime/descriptors.runtime.iml
+++ b/core/descriptors.runtime/descriptors.runtime.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/core/descriptors/descriptors.iml b/core/descriptors/descriptors.iml
index 6ad1613764c..267079fc9dd 100644
--- a/core/descriptors/descriptors.iml
+++ b/core/descriptors/descriptors.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/core/deserialization/deserialization.iml b/core/deserialization/deserialization.iml
index 6ec426f69b4..2303e1ffb8f 100644
--- a/core/deserialization/deserialization.iml
+++ b/core/deserialization/deserialization.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/core/reflection.jvm/reflection.jvm.iml b/core/reflection.jvm/reflection.jvm.iml
index 73f4dacbda7..b1e488def16 100644
--- a/core/reflection.jvm/reflection.jvm.iml
+++ b/core/reflection.jvm/reflection.jvm.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/core/runtime.jvm/runtime.jvm.iml b/core/runtime.jvm/runtime.jvm.iml
index bc71bb10774..f4dd9ec6a0b 100644
--- a/core/runtime.jvm/runtime.jvm.iml
+++ b/core/runtime.jvm/runtime.jvm.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/core/script.runtime/script.runtime.iml b/core/script.runtime/script.runtime.iml
index bc71bb10774..f4dd9ec6a0b 100644
--- a/core/script.runtime/script.runtime.iml
+++ b/core/script.runtime/script.runtime.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/core/util.runtime/util.runtime.iml b/core/util.runtime/util.runtime.iml
index f1f19e59f74..1d05813c096 100644
--- a/core/util.runtime/util.runtime.iml
+++ b/core/util.runtime/util.runtime.iml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_6" inherit-compiler-output="true">
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />