diff --git a/java-decompiler-engine.iml b/java-decompiler-engine.iml
index 5880ebf..f5977f4 100644
--- a/java-decompiler-engine.iml
+++ b/java-decompiler-engine.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/src/org/jetbrains/java/decompiler/modules/decompiler/ConcatenationHelper.java b/src/org/jetbrains/java/decompiler/modules/decompiler/ConcatenationHelper.java
index 7d7b33d..90d2732 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/ConcatenationHelper.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/ConcatenationHelper.java
@@ -160,7 +160,7 @@ public class ConcatenationHelper {
       if (constant.type == CodeConstants.CONSTANT_String) {
         String recipe = ((PrimitiveConstant)constant).getString();
 
-        List<Exprent> res = new ArrayList<>();
+        List<Exprent> res = new ArrayList<Exprent>();
         StringBuilder acc = new StringBuilder();
         int parameterId = 0;
         for (int i = 0; i < recipe.length(); i++) {
@@ -195,7 +195,7 @@ public class ConcatenationHelper {
         return res;
       }
     }
-    return new ArrayList<>(parameters);
+    return new ArrayList<Exprent>(parameters);
   }
 
   private static boolean isAppendConcat(InvocationExprent expr, VarType cltype) {