diff --git a/runtime/Java/src/org/antlr/v4/runtime/SymbolStream.java b/runtime/Java/src/org/antlr/v4/runtime/SymbolStream.java
index 4c801b1dc..fcab38a0f 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/SymbolStream.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/SymbolStream.java
@@ -31,19 +31,21 @@ package org.antlr.v4.runtime;
 
 /**  A stream of either tokens or tree nodes */
 public interface SymbolStream<T> extends IntStream {
-	/** Get an object at absolute index i; 0..n-1.
+	/** Get the symbol at absolute index i; 0..n-1.
 	 *  This is only valid if the underlying stream implementation buffers
 	 *  all of the incoming objects.
+	 *
+	 *  @throws UnsupportedOperationException if the index {@code i} is outside
+	 *    the marked region and the stream does not support accessing symbols by
+	 *    index outside of marked regions.
 	 */
 	public T get(int i);
 
-	/** Get Object at current input pointer + i ahead where i=1 is next Object.
-	 *  i<0 indicates Objects in the past.  So -1 is previous Object and -2 is
-	 *  two Objects ago. LT(0) is undefined.  For i>=n, return an
-	 *  object representing EOF. Return null for LT(0) and any index that
-	 *  results in an absolute index that is negative.
-	 *
-	 *  TODO (Sam): throw exception for invalid k?
+	/** Get symbol at current input pointer + {@code k} ahead where {@code k=1}
+	 *  is next symbol. k&lt;0 indicates objects in the past.  So -1 is previous
+	 *  Object and -2 is two Objects ago. {@code LT(0)} is undefined.  For i>=n,
+	 *  return an object representing EOF. Return {@code null} for {@code LT(0)}
+	 *  and any index that results in an absolute index that is negative.
 	 */
 	T LT(int k);
 }