diff --git a/runtime/Java/src/org/antlr/v4/runtime/ANTLRStringStream.java b/runtime/Java/src/org/antlr/v4/runtime/ANTLRStringStream.java
index e8f427b92..153d78458 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/ANTLRStringStream.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/ANTLRStringStream.java
@@ -58,7 +58,7 @@ public class ANTLRStringStream implements CharStream {
 	 *  move through the input stream.  Indexed from 1..markDepth.
      *  A null is kept @ index 0.  Create upon first call to mark().
 	 */
-	protected List markers;
+	protected List<CharStreamState> markers;
 
 	/** Track the last mark() call result value for use in rewind(). */
 	protected int lastMarker;
@@ -149,17 +149,17 @@ public class ANTLRStringStream implements CharStream {
 
 	public int mark() {
         if ( markers==null ) {
-            markers = new ArrayList();
+            markers = new ArrayList<CharStreamState>();
             markers.add(null); // depth 0
         }
         markDepth++;
-		CharStreamState state = null;
+		CharStreamState state;
 		if ( markDepth>=markers.size() ) {
 			state = new CharStreamState();
 			markers.add(state);
 		}
 		else {
-			state = (CharStreamState)markers.get(markDepth);
+			state = markers.get(markDepth);
 		}
 		state.p = p;
 		state.line = line;
@@ -169,7 +169,7 @@ public class ANTLRStringStream implements CharStream {
     }
 
     public void rewind(int m) {
-		CharStreamState state = (CharStreamState)markers.get(m);
+		CharStreamState state = markers.get(m);
 		// restore stream state
 		seek(state.p);
 		line = state.line;