diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AnnotationExprent.java b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AnnotationExprent.java
index 13491fc..c9c9c7f 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AnnotationExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AnnotationExprent.java
@@ -17,10 +17,10 @@ public class AnnotationExprent extends Exprent {
   public static final int ANNOTATION_SINGLE_ELEMENT = 3;
 
   private final String className;
-  private final List<String> parNames;
-  private final List<Exprent> parValues;
+  private final List<? extends String> parNames;
+  private final List<? extends Exprent> parValues;
 
-  public AnnotationExprent(String className, List<String> parNames, List<Exprent> parValues) {
+  public AnnotationExprent(String className, List<? extends String> parNames, List<? extends Exprent> parValues) {
     super(EXPRENT_ANNOTATION);
     this.className = className;
     this.parNames = parNames;
diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AssertExprent.java b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AssertExprent.java
index 0ae9fee..0dcb63d 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AssertExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/AssertExprent.java
@@ -10,9 +10,9 @@ import java.util.List;
 
 public class AssertExprent extends Exprent {
 
-  private final List<Exprent> parameters;
+  private final List<? extends Exprent> parameters;
 
-  public AssertExprent(List<Exprent> parameters) {
+  public AssertExprent(List<? extends Exprent> parameters) {
     super(EXPRENT_ASSERT);
     this.parameters = parameters;
   }
diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java
index 8472cef..1abaf32 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java
@@ -66,7 +66,7 @@ public class InvocationExprent extends Exprent {
   public InvocationExprent(int opcode,
                            LinkConstant cn,
                            List<PooledConstant> bootstrapArguments,
-                           ListStack<Exprent> stack,
+                           ListStack<? extends Exprent> stack,
                            Set<Integer> bytecodeOffsets) {
     this();
 
diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/GeneralStatement.java b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/GeneralStatement.java
index 56ada55..0891a47 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/GeneralStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/GeneralStatement.java
@@ -18,7 +18,7 @@ public class GeneralStatement extends Statement {
     type = Statement.TYPE_GENERAL;
   }
 
-  public GeneralStatement(Statement head, Collection<Statement> statements, Statement post) {
+  public GeneralStatement(Statement head, Collection<? extends Statement> statements, Statement post) {
 
     this();
 
diff --git a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SequenceStatement.java b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SequenceStatement.java
index 7acad0c..8aa6adc 100644
--- a/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SequenceStatement.java
+++ b/src/org/jetbrains/java/decompiler/modules/decompiler/stats/SequenceStatement.java
@@ -22,7 +22,7 @@ public class SequenceStatement extends Statement {
     type = Statement.TYPE_SEQUENCE;
   }
 
-  public SequenceStatement(List<Statement> lst) {
+  public SequenceStatement(List<? extends Statement> lst) {
 
     this();
 
diff --git a/src/org/jetbrains/java/decompiler/util/FastSparseSetFactory.java b/src/org/jetbrains/java/decompiler/util/FastSparseSetFactory.java
index 08bf156..b955139 100644
--- a/src/org/jetbrains/java/decompiler/util/FastSparseSetFactory.java
+++ b/src/org/jetbrains/java/decompiler/util/FastSparseSetFactory.java
@@ -14,7 +14,7 @@ public class FastSparseSetFactory<E> {
 
   private int lastMask;
 
-  public FastSparseSetFactory(Collection<E> set) {
+  public FastSparseSetFactory(Collection<? extends E> set) {
 
     int block = -1;
     int mask = -1;
diff --git a/src/org/jetbrains/java/decompiler/util/ListStack.java b/src/org/jetbrains/java/decompiler/util/ListStack.java
index d5ae774..ac0dad9 100644
--- a/src/org/jetbrains/java/decompiler/util/ListStack.java
+++ b/src/org/jetbrains/java/decompiler/util/ListStack.java
@@ -10,7 +10,7 @@ public class ListStack<T> extends ArrayList<T> {
     super();
   }
 
-  public ListStack(ArrayList<T> list) {
+  public ListStack(ArrayList<? extends T> list) {
     super(list);
   }