diff --git a/runtime/Java/src/org/antlr/v4/runtime/BaseRecognizer.java b/runtime/Java/src/org/antlr/v4/runtime/BaseRecognizer.java
index d50cdc588..ccbbe7551 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/BaseRecognizer.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/BaseRecognizer.java
@@ -148,7 +148,7 @@ public abstract class BaseRecognizer<TSymbol> extends Recognizer<TSymbol, Parser
 	}
 
 	@Override
-	public abstract ObjectStream<TSymbol> getInputStream();
+	public abstract SymbolStream<TSymbol> getInputStream();
 
 	/** Match needs to return the current input symbol, which gets put
 	 *  into the label for the associated token ref; e.g., x=ID.  Token
diff --git a/runtime/Java/src/org/antlr/v4/runtime/DefaultANTLRErrorStrategy.java b/runtime/Java/src/org/antlr/v4/runtime/DefaultANTLRErrorStrategy.java
index dd3c00a79..48a6734b0 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/DefaultANTLRErrorStrategy.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/DefaultANTLRErrorStrategy.java
@@ -33,8 +33,6 @@ import com.sun.istack.internal.NotNull;
 import org.antlr.v4.runtime.atn.*;
 import org.antlr.v4.runtime.misc.IntervalSet;
 import org.antlr.v4.runtime.tree.AST;
-import org.antlr.v4.runtime.tree.ASTAdaptor;
-import org.antlr.v4.runtime.tree.Tree;
 
 /** This is the default error handling mechanism for ANTLR parsers
  *  and tree parsers.
@@ -158,7 +156,7 @@ public class DefaultANTLRErrorStrategy<TSymbol> implements ANTLRErrorStrategy<TS
 //		System.err.println("sync expecting: "+expecting);
 
 		// TODO: subclass this class for treeparsers
-		ObjectStream<TSymbol> tokens = recognizer.getInputStream();
+		SymbolStream<TSymbol> tokens = recognizer.getInputStream();
 		int la = tokens.LA(1);
 		// Return but don't end recovery. only do that upon valid token match
 		if ( la==Token.EOF || expecting.contains(la) ) return;
@@ -187,7 +185,7 @@ public class DefaultANTLRErrorStrategy<TSymbol> implements ANTLRErrorStrategy<TS
 										  NoViableAltException e)
 	throws RecognitionException
 	{
-		ObjectStream<TSymbol> tokens = recognizer.getInputStream();
+		SymbolStream<TSymbol> tokens = recognizer.getInputStream();
 		String input;
 		if (tokens instanceof TokenStream) {
 			input = ((TokenStream)tokens).toString(e.startToken, e.offendingToken);
diff --git a/runtime/Java/src/org/antlr/v4/runtime/NoViableAltException.java b/runtime/Java/src/org/antlr/v4/runtime/NoViableAltException.java
index 60ac61012..88d48a5bd 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/NoViableAltException.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/NoViableAltException.java
@@ -55,7 +55,7 @@ public class NoViableAltException extends RecognitionException {
 	}
 
 	public <T> NoViableAltException(BaseRecognizer<T> recognizer,
-								ObjectStream<T> input,
+								SymbolStream<T> input,
 								Token startToken,
 								Token offendingToken,
 								T offendingNode,
diff --git a/runtime/Java/src/org/antlr/v4/runtime/ObjectStream.java b/runtime/Java/src/org/antlr/v4/runtime/SymbolStream.java
similarity index 97%
rename from runtime/Java/src/org/antlr/v4/runtime/ObjectStream.java
rename to runtime/Java/src/org/antlr/v4/runtime/SymbolStream.java
index 65595e0a0..4c801b1dc 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/ObjectStream.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/SymbolStream.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.runtime;
 
 /**  A stream of either tokens or tree nodes */
-public interface ObjectStream<T> extends IntStream {
+public interface SymbolStream<T> extends IntStream {
 	/** Get an object at absolute index i; 0..n-1.
 	 *  This is only valid if the underlying stream implementation buffers
 	 *  all of the incoming objects.
diff --git a/runtime/Java/src/org/antlr/v4/runtime/TokenStream.java b/runtime/Java/src/org/antlr/v4/runtime/TokenStream.java
index 5a4fed693..7f0b1ee4f 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/TokenStream.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/TokenStream.java
@@ -30,7 +30,7 @@
 package org.antlr.v4.runtime;
 
 /** A stream of tokens accessing tokens from a TokenSource */
-public interface TokenStream extends ObjectStream<Token> {
+public interface TokenStream extends SymbolStream<Token> {
     /** Get Token at current input pointer + i ahead where i=1 is next Token.
 	 *  i<0 indicates tokens in the past.  So -1 is previous token and -2 is
 	 *  two tokens ago. LT(0) is undefined.  For i>=n, return Token.EOFToken.
diff --git a/runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java b/runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
index 43fb6583e..d37b51ad0 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
@@ -83,7 +83,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 //		System.out.println(dot.getDOT(atn.rules.get(1), parser.getRuleNames()));
 	}
 
-	public int adaptivePredict(ObjectStream<TSymbol> input, int decision, RuleContext outerContext) {
+	public int adaptivePredict(SymbolStream<TSymbol> input, int decision, RuleContext outerContext) {
 		predict_calls++;
 		DFA dfa = decisionToDFA[decision];
 		if ( dfa==null || dfa.s0==null ) {
@@ -108,7 +108,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 		}
 	}
 
-	public int predictATN(DFA dfa, ObjectStream<TSymbol> input,
+	public int predictATN(DFA dfa, SymbolStream<TSymbol> input,
 						  RuleContext outerContext,
 						  boolean useContext)
 	{
@@ -146,7 +146,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 	}
 
 	// doesn't create DFA when matching
-	public int matchATN(ObjectStream<TSymbol> input, ATNState startState) {
+	public int matchATN(SymbolStream<TSymbol> input, ATNState startState) {
 		DFA dfa = new DFA(startState);
 		if ( outerContext==null ) outerContext = RuleContext.EMPTY;
 		RuleContext ctx = RuleContext.EMPTY;
@@ -154,7 +154,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 		return execATN(input, dfa, input.index(), s0_closure, false);
 	}
 
-	public int execDFA(ObjectStream<TSymbol> input, DFA dfa, DFAState s0, RuleContext outerContext) {
+	public int execDFA(SymbolStream<TSymbol> input, DFA dfa, DFAState s0, RuleContext outerContext) {
 //		dump(dfa);
 		if ( outerContext==null ) outerContext = RuleContext.EMPTY;
 		this.outerContext = outerContext;
@@ -241,7 +241,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 		return prevAcceptState.prediction;
 	}
 
-	public String getInputString(ObjectStream<TSymbol> input, int start) {
+	public String getInputString(SymbolStream<TSymbol> input, int start) {
 		if ( input instanceof TokenStream ) {
 			return ((TokenStream)input).toString(start,input.index());
 		}
@@ -251,7 +251,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 		return "n/a";
 	}
 
-	public int execATN(ObjectStream<TSymbol> input,
+	public int execATN(SymbolStream<TSymbol> input,
 					   DFA dfa,
 					   int startIndex,
 					   OrderedHashSet<ATNConfig> s0,
@@ -405,7 +405,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 		return exitAlt;
 	}
 
-	public int retryWithContext(ObjectStream<TSymbol> input,
+	public int retryWithContext(SymbolStream<TSymbol> input,
 								DFA dfa,
 								int startIndex,
 								RuleContext originalContext,
@@ -823,7 +823,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 		return String.valueOf(t);
 	}
 
-	public String getLookaheadName(ObjectStream<TSymbol> input) {
+	public String getLookaheadName(SymbolStream<TSymbol> input) {
 		return getTokenName(input.LA(1));
 	}
 
@@ -849,7 +849,7 @@ public class ParserATNSimulator<TSymbol> extends ATNSimulator {
 		}
 	}
 
-	public int throwNoViableAlt(ObjectStream<TSymbol> input, RuleContext outerContext,
+	public int throwNoViableAlt(SymbolStream<TSymbol> input, RuleContext outerContext,
 								OrderedHashSet<ATNConfig> configs, int startIndex)
 	{
 		if ( parser instanceof TreeParser) {
diff --git a/runtime/Java/src/org/antlr/v4/runtime/tree/ASTNodeStream.java b/runtime/Java/src/org/antlr/v4/runtime/tree/ASTNodeStream.java
index c6e455dad..961f1d85b 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/tree/ASTNodeStream.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/tree/ASTNodeStream.java
@@ -32,7 +32,7 @@ package org.antlr.v4.runtime.tree;
 import org.antlr.v4.runtime.*;
 
 /** A stream of tree nodes, accessing nodes from a tree of some kind */
-public interface ASTNodeStream<T> extends ObjectStream<T> {
+public interface ASTNodeStream<T> extends SymbolStream<T> {
 	/** Get a tree node at an absolute index i; 0..n-1.
 	 *  If you don't want to buffer up nodes, then this method makes no
 	 *  sense for you.