diff --git a/runtime/Cpp/runtime/antlr4cpp-vs2013.vcxproj b/runtime/Cpp/runtime/antlr4cpp-vs2013.vcxproj
index 1eb43a563..50ab20c8b 100644
--- a/runtime/Cpp/runtime/antlr4cpp-vs2013.vcxproj
+++ b/runtime/Cpp/runtime/antlr4cpp-vs2013.vcxproj
@@ -549,7 +549,6 @@
     <ClInclude Include="src\InputMismatchException.h" />
     <ClInclude Include="src\InterpreterRuleContext.h" />
     <ClInclude Include="src\IntStream.h" />
-    <ClInclude Include="src\IRecognizer.h" />
     <ClInclude Include="src\Lexer.h" />
     <ClInclude Include="src\LexerInterpreter.h" />
     <ClInclude Include="src\LexerNoViableAltException.h" />
@@ -621,4 +620,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/runtime/Cpp/runtime/antlr4cpp-vs2013.vcxproj.filters b/runtime/Cpp/runtime/antlr4cpp-vs2013.vcxproj.filters
index 4ad93b5cc..d3b301654 100644
--- a/runtime/Cpp/runtime/antlr4cpp-vs2013.vcxproj.filters
+++ b/runtime/Cpp/runtime/antlr4cpp-vs2013.vcxproj.filters
@@ -114,9 +114,6 @@
     <ClInclude Include="src\IntStream.h">
       <Filter>Header Files</Filter>
     </ClInclude>
-    <ClInclude Include="src\IRecognizer.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
     <ClInclude Include="src\Lexer.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -942,4 +939,4 @@
       <Filter>Source Files\tree</Filter>
     </ClCompile>
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/runtime/Cpp/runtime/antlr4cpp-vs2015.vcxproj b/runtime/Cpp/runtime/antlr4cpp-vs2015.vcxproj
index 85fa3da44..e549a78b6 100644
--- a/runtime/Cpp/runtime/antlr4cpp-vs2015.vcxproj
+++ b/runtime/Cpp/runtime/antlr4cpp-vs2015.vcxproj
@@ -562,7 +562,6 @@
     <ClInclude Include="src\InputMismatchException.h" />
     <ClInclude Include="src\InterpreterRuleContext.h" />
     <ClInclude Include="src\IntStream.h" />
-    <ClInclude Include="src\IRecognizer.h" />
     <ClInclude Include="src\Lexer.h" />
     <ClInclude Include="src\LexerInterpreter.h" />
     <ClInclude Include="src\LexerNoViableAltException.h" />
@@ -634,4 +633,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/runtime/Cpp/runtime/antlr4cpp-vs2015.vcxproj.filters b/runtime/Cpp/runtime/antlr4cpp-vs2015.vcxproj.filters
index 3d77916e6..21eaaf722 100644
--- a/runtime/Cpp/runtime/antlr4cpp-vs2015.vcxproj.filters
+++ b/runtime/Cpp/runtime/antlr4cpp-vs2015.vcxproj.filters
@@ -114,9 +114,6 @@
     <ClInclude Include="src\IntStream.h">
       <Filter>Header Files</Filter>
     </ClInclude>
-    <ClInclude Include="src\IRecognizer.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
     <ClInclude Include="src\Lexer.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -942,4 +939,4 @@
       <Filter>Source Files\tree</Filter>
     </ClCompile>
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/runtime/Cpp/runtime/src/ANTLRErrorListener.h b/runtime/Cpp/runtime/src/ANTLRErrorListener.h
index 7729b2537..888e4fa45 100755
--- a/runtime/Cpp/runtime/src/ANTLRErrorListener.h
+++ b/runtime/Cpp/runtime/src/ANTLRErrorListener.h
@@ -50,7 +50,7 @@ namespace antlr4 {
     ///        the reporting of an error. It is null in the case where
     ///        the parser was able to recover in line without exiting the
     ///        surrounding rule. </param>
-    virtual void syntaxError(IRecognizer *recognizer, Token *offendingSymbol, size_t line,
+    virtual void syntaxError(Recognizer *recognizer, Token *offendingSymbol, size_t line,
                              size_t charPositionInLine, const std::string &msg, std::exception_ptr e) = 0;
 
     /**
diff --git a/runtime/Cpp/runtime/src/BaseErrorListener.cpp b/runtime/Cpp/runtime/src/BaseErrorListener.cpp
index 47ef00cbf..89b9510e1 100755
--- a/runtime/Cpp/runtime/src/BaseErrorListener.cpp
+++ b/runtime/Cpp/runtime/src/BaseErrorListener.cpp
@@ -8,7 +8,7 @@
 
 using namespace antlr4;
 
-void BaseErrorListener::syntaxError(IRecognizer * /*recognizer*/, Token * /*offendingSymbol*/, size_t /*line*/,
+void BaseErrorListener::syntaxError(Recognizer * /*recognizer*/, Token * /*offendingSymbol*/, size_t /*line*/,
   size_t /*charPositionInLine*/, const std::string &/*msg*/, std::exception_ptr /*e*/) {
 }
 
diff --git a/runtime/Cpp/runtime/src/BaseErrorListener.h b/runtime/Cpp/runtime/src/BaseErrorListener.h
index 75aefc60a..069e8bd8f 100755
--- a/runtime/Cpp/runtime/src/BaseErrorListener.h
+++ b/runtime/Cpp/runtime/src/BaseErrorListener.h
@@ -20,7 +20,7 @@ namespace antlr4 {
    */
   class ANTLR4CPP_PUBLIC BaseErrorListener : public ANTLRErrorListener {
 
-    virtual void syntaxError(IRecognizer *recognizer, Token * offendingSymbol, size_t line, size_t charPositionInLine,
+    virtual void syntaxError(Recognizer *recognizer, Token * offendingSymbol, size_t line, size_t charPositionInLine,
       const std::string &msg, std::exception_ptr e) override;
 
     virtual void reportAmbiguity(Parser *recognizer, const dfa::DFA &dfa, size_t startIndex, size_t stopIndex, bool exact,
diff --git a/runtime/Cpp/runtime/src/ConsoleErrorListener.cpp b/runtime/Cpp/runtime/src/ConsoleErrorListener.cpp
index 3f06925f8..7ab242db2 100755
--- a/runtime/Cpp/runtime/src/ConsoleErrorListener.cpp
+++ b/runtime/Cpp/runtime/src/ConsoleErrorListener.cpp
@@ -9,7 +9,7 @@ using namespace antlr4;
 
 ConsoleErrorListener ConsoleErrorListener::INSTANCE;
 
-void ConsoleErrorListener::syntaxError(IRecognizer * /*recognizer*/, Token * /*offendingSymbol*/,
+void ConsoleErrorListener::syntaxError(Recognizer * /*recognizer*/, Token * /*offendingSymbol*/,
   size_t line, size_t charPositionInLine, const std::string &msg, std::exception_ptr /*e*/)  {
   std::cerr << "line " << line << ":" << charPositionInLine << " " << msg << std::endl;
 }
diff --git a/runtime/Cpp/runtime/src/ConsoleErrorListener.h b/runtime/Cpp/runtime/src/ConsoleErrorListener.h
index a0869b6ad..4df9d6919 100755
--- a/runtime/Cpp/runtime/src/ConsoleErrorListener.h
+++ b/runtime/Cpp/runtime/src/ConsoleErrorListener.h
@@ -28,7 +28,7 @@ namespace antlr4 {
      * line <em>line</em>:<em>charPositionInLine</em> <em>msg</em>
      * </pre>
      */
-    virtual void syntaxError(IRecognizer *recognizer, Token * offendingSymbol, size_t line, size_t charPositionInLine,
+    virtual void syntaxError(Recognizer *recognizer, Token * offendingSymbol, size_t line, size_t charPositionInLine,
                              const std::string &msg, std::exception_ptr e) override;
   };
 
diff --git a/runtime/Cpp/runtime/src/IRecognizer.h b/runtime/Cpp/runtime/src/IRecognizer.h
deleted file mode 100644
index 4c247c740..000000000
--- a/runtime/Cpp/runtime/src/IRecognizer.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/* Copyright (c) 2012-2016 The ANTLR Project. All rights reserved.
- * Use of this file is governed by the BSD 3-clause license that
- * can be found in the LICENSE.txt file in the project root.
- */
-
-#pragma once
-
-namespace antlr4 {
-
-  class ANTLR4CPP_PUBLIC IRecognizer {
-  public:
-    virtual ~IRecognizer() {};
-
-    virtual size_t getState() const = 0;
-
-    // Get the ATN used by the recognizer for prediction.
-    virtual const atn::ATN& getATN() const = 0;
-
-  };
-
-} // namespace antlr4
diff --git a/runtime/Cpp/runtime/src/ProxyErrorListener.cpp b/runtime/Cpp/runtime/src/ProxyErrorListener.cpp
index 45ad43c22..b1f43d100 100755
--- a/runtime/Cpp/runtime/src/ProxyErrorListener.cpp
+++ b/runtime/Cpp/runtime/src/ProxyErrorListener.cpp
@@ -23,7 +23,7 @@ void ProxyErrorListener::removeErrorListeners() {
   _delegates.clear();
 }
 
-void ProxyErrorListener::syntaxError(IRecognizer *recognizer, Token *offendingSymbol, size_t line,
+void ProxyErrorListener::syntaxError(Recognizer *recognizer, Token *offendingSymbol, size_t line,
   size_t charPositionInLine, const std::string &msg, std::exception_ptr e) {
 
   for (auto listener : _delegates) {
diff --git a/runtime/Cpp/runtime/src/ProxyErrorListener.h b/runtime/Cpp/runtime/src/ProxyErrorListener.h
index f2d8d47ea..2b0b43562 100755
--- a/runtime/Cpp/runtime/src/ProxyErrorListener.h
+++ b/runtime/Cpp/runtime/src/ProxyErrorListener.h
@@ -22,7 +22,7 @@ namespace antlr4 {
     void removeErrorListener(ANTLRErrorListener *listener);
     void removeErrorListeners();
 
-    void syntaxError(IRecognizer *recognizer, Token *offendingSymbol, size_t line, size_t charPositionInLine,
+    void syntaxError(Recognizer *recognizer, Token *offendingSymbol, size_t line, size_t charPositionInLine,
                      const std::string &msg, std::exception_ptr e) override;
 
     virtual void reportAmbiguity(Parser *recognizer, const dfa::DFA &dfa, size_t startIndex, size_t stopIndex, bool exact,
diff --git a/runtime/Cpp/runtime/src/RecognitionException.cpp b/runtime/Cpp/runtime/src/RecognitionException.cpp
index 608497fed..b51308feb 100755
--- a/runtime/Cpp/runtime/src/RecognitionException.cpp
+++ b/runtime/Cpp/runtime/src/RecognitionException.cpp
@@ -13,12 +13,12 @@
 
 using namespace antlr4;
 
-RecognitionException::RecognitionException(IRecognizer *recognizer, IntStream *input, ParserRuleContext *ctx,
+RecognitionException::RecognitionException(Recognizer *recognizer, IntStream *input, ParserRuleContext *ctx,
                                            Token *offendingToken)
   : RecognitionException("", recognizer, input, ctx, offendingToken) {
 }
 
-RecognitionException::RecognitionException(const std::string &message, IRecognizer *recognizer, IntStream *input,
+RecognitionException::RecognitionException(const std::string &message, Recognizer *recognizer, IntStream *input,
                                            ParserRuleContext *ctx, Token *offendingToken)
   : RuntimeException(message), _recognizer(recognizer), _input(input), _ctx(ctx), _offendingToken(offendingToken) {
   InitializeInstanceFields();
@@ -54,7 +54,7 @@ Token* RecognitionException::getOffendingToken() const {
   return _offendingToken;
 }
 
-IRecognizer* RecognitionException::getRecognizer() const {
+Recognizer* RecognitionException::getRecognizer() const {
   return _recognizer;
 }
 
diff --git a/runtime/Cpp/runtime/src/RecognitionException.h b/runtime/Cpp/runtime/src/RecognitionException.h
index b444cbcbf..0e4dc88a1 100755
--- a/runtime/Cpp/runtime/src/RecognitionException.h
+++ b/runtime/Cpp/runtime/src/RecognitionException.h
@@ -17,7 +17,7 @@ namespace antlr4 {
   class ANTLR4CPP_PUBLIC RecognitionException : public RuntimeException {
   private:
     /// The Recognizer where this exception originated.
-    IRecognizer *_recognizer;
+    Recognizer *_recognizer;
     IntStream *_input;
     ParserRuleContext *_ctx;
 
@@ -29,9 +29,9 @@ namespace antlr4 {
     size_t _offendingState;
 
   public:
-    RecognitionException(IRecognizer *recognizer, IntStream *input, ParserRuleContext *ctx,
+    RecognitionException(Recognizer *recognizer, IntStream *input, ParserRuleContext *ctx,
                          Token *offendingToken = nullptr);
-    RecognitionException(const std::string &message, IRecognizer *recognizer, IntStream *input,
+    RecognitionException(const std::string &message, Recognizer *recognizer, IntStream *input,
                          ParserRuleContext *ctx, Token *offendingToken = nullptr);
     ~RecognitionException() {}
 
@@ -87,7 +87,7 @@ namespace antlr4 {
     /// </summary>
     /// <returns> The recognizer where this exception occurred, or {@code null} if
     /// the recognizer is not available. </returns>
-    virtual IRecognizer* getRecognizer() const;
+    virtual Recognizer* getRecognizer() const;
 
   private:
     void InitializeInstanceFields();
diff --git a/runtime/Cpp/runtime/src/Recognizer.h b/runtime/Cpp/runtime/src/Recognizer.h
index 846e132d8..0a22e9116 100755
--- a/runtime/Cpp/runtime/src/Recognizer.h
+++ b/runtime/Cpp/runtime/src/Recognizer.h
@@ -6,11 +6,10 @@
 #pragma once
 
 #include "ProxyErrorListener.h"
-#include "IRecognizer.h"
 
 namespace antlr4 {
 
-  class ANTLR4CPP_PUBLIC Recognizer : public IRecognizer {
+  class ANTLR4CPP_PUBLIC Recognizer {
   public:
     static const size_t EOF = (size_t)-1;
 
@@ -117,7 +116,10 @@ namespace antlr4 {
 
     virtual void action(RuleContext *localctx, size_t ruleIndex, size_t actionIndex);
 
-    virtual size_t getState() const override;
+    virtual size_t getState() const ;
+
+    // Get the ATN used by the recognizer for prediction.
+    virtual const atn::ATN& getATN() const = 0;
 
     /// <summary>
     /// Indicate that the recognizer has changed internal state that is
diff --git a/runtime/Cpp/runtime/src/antlr4-runtime.h b/runtime/Cpp/runtime/src/antlr4-runtime.h
index 9f854728b..8009c4ff1 100644
--- a/runtime/Cpp/runtime/src/antlr4-runtime.h
+++ b/runtime/Cpp/runtime/src/antlr4-runtime.h
@@ -25,7 +25,6 @@
 #include "DiagnosticErrorListener.h"
 #include "Exceptions.h"
 #include "FailedPredicateException.h"
-#include "IRecognizer.h"
 #include "InputMismatchException.h"
 #include "IntStream.h"
 #include "InterpreterRuleContext.h"
diff --git a/runtime/Cpp/runtime/src/support/Declarations.h b/runtime/Cpp/runtime/src/support/Declarations.h
index 2172735d5..32a88de36 100644
--- a/runtime/Cpp/runtime/src/support/Declarations.h
+++ b/runtime/Cpp/runtime/src/support/Declarations.h
@@ -34,7 +34,6 @@ namespace antlr4 {
   class InputMismatchException;
   class IntStream;
   class InterpreterRuleContext;
-  class IRecognizer;
   class Lexer;
   class LexerInterpreter;
   class LexerNoViableAltException;
diff --git a/runtime/Cpp/runtime/src/tree/xpath/XPathLexerErrorListener.cpp b/runtime/Cpp/runtime/src/tree/xpath/XPathLexerErrorListener.cpp
index aa678e833..089eec1d2 100755
--- a/runtime/Cpp/runtime/src/tree/xpath/XPathLexerErrorListener.cpp
+++ b/runtime/Cpp/runtime/src/tree/xpath/XPathLexerErrorListener.cpp
@@ -8,6 +8,6 @@
 using namespace antlr4;
 using namespace antlr4::tree::xpath;
 
-void XPathLexerErrorListener::syntaxError(IRecognizer * /*recognizer*/, Token * /*offendingSymbol*/,
+void XPathLexerErrorListener::syntaxError(Recognizer * /*recognizer*/, Token * /*offendingSymbol*/,
   size_t /*line*/, size_t /*charPositionInLine*/, const std::string &/*msg*/, std::exception_ptr /*e*/) {
 }
diff --git a/runtime/Cpp/runtime/src/tree/xpath/XPathLexerErrorListener.h b/runtime/Cpp/runtime/src/tree/xpath/XPathLexerErrorListener.h
index f6c51cb93..dba7a5167 100755
--- a/runtime/Cpp/runtime/src/tree/xpath/XPathLexerErrorListener.h
+++ b/runtime/Cpp/runtime/src/tree/xpath/XPathLexerErrorListener.h
@@ -13,7 +13,7 @@ namespace xpath {
 
   class ANTLR4CPP_PUBLIC XPathLexerErrorListener : public BaseErrorListener {
   public:
-    virtual void syntaxError(IRecognizer *recognizer, Token *offendingSymbol, size_t line,
+    virtual void syntaxError(Recognizer *recognizer, Token *offendingSymbol, size_t line,
       size_t charPositionInLine, const std::string &msg, std::exception_ptr e) override;
   };