diff --git a/source/adios2/CMakeLists.txt b/source/adios2/CMakeLists.txt
index 5bc3f9c121..99b413542c 100644
--- a/source/adios2/CMakeLists.txt
+++ b/source/adios2/CMakeLists.txt
@@ -139,7 +139,7 @@ if (ADIOS2_HAVE_Derived_Variable)
   find_package(BISON "3.8.2")
   find_package(FLEX)
 
-  if(NOT BISON_FOUND OR NOT FLEX_FOUND)
+  if(NOT BISON_FOUND OR NOT FLEX_FOUND OR (NOT BISON_VERSION VERSION_GREATER_EQUAL "3.8.2"))
     include(ADIOSBisonFlexSub)
     SETUP_ADIOS_BISON_FLEX_SUB()
   else()
@@ -155,13 +155,15 @@ if (ADIOS2_HAVE_Derived_Variable)
       DEFINES_FILE ${CMAKE_CURRENT_BINARY_DIR}/lexer.h)
     ADD_FLEX_BISON_DEPENDENCY(MyScanner MyParser)
   endif()
-  if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
     SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_BINARY_DIR}/lexer.cpp PROPERTIES COMPILE_FLAGS -Wno-sign-compare)
-  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
+  elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Intel")
     SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_BINARY_DIR}/parser.cpp PROPERTIES COMPILE_FLAGS -Wno-unused-but-set-variable)
-  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "IntelLLVM")
+  elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "AppleClang")
     SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_BINARY_DIR}/parser.cpp PROPERTIES COMPILE_FLAGS -Wno-unused-but-set-variable)
-  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+  elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "IntelLLVM")
+    SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_BINARY_DIR}/parser.cpp PROPERTIES COMPILE_FLAGS -Wno-unused-but-set-variable)
+  elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
     SET_SOURCE_FILES_PROPERTIES(toolkit/derived/Expression.cpp toolkit/derived/Function.cpp PROPERTIES COMPILE_FLAGS "/wd4005 /wd4065 /wd4267 -DYY_NO_UNISTD_H")
   endif()
   add_library(adios2_core_derived
diff --git a/source/adios2/toolkit/derived/parser/ASTDriver.cpp b/source/adios2/toolkit/derived/parser/ASTDriver.cpp
index 53871e0db8..c3afaf576f 100644
--- a/source/adios2/toolkit/derived/parser/ASTDriver.cpp
+++ b/source/adios2/toolkit/derived/parser/ASTDriver.cpp
@@ -13,6 +13,7 @@ ASTDriver::ASTDriver(const std::string input) { ASTDriver::parse(input); }
 
 ASTDriver::~ASTDriver()
 {
+    ASTDriver::destroy_lex_structures();
     while (holding.size() > 0)
     {
         delete holding.top();
diff --git a/source/adios2/toolkit/derived/parser/ASTDriver.h b/source/adios2/toolkit/derived/parser/ASTDriver.h
index c1f2855800..9f4b01b790 100644
--- a/source/adios2/toolkit/derived/parser/ASTDriver.h
+++ b/source/adios2/toolkit/derived/parser/ASTDriver.h
@@ -27,6 +27,7 @@ class ASTDriver
 
     // Defined in lexer.l
     void parse(const std::string input);
+    void destroy_lex_structures();
 
     ASTNode *getAST();
 
diff --git a/source/adios2/toolkit/derived/parser/lexer.l b/source/adios2/toolkit/derived/parser/lexer.l
index 566e4a41c7..ffa52ed5ce 100644
--- a/source/adios2/toolkit/derived/parser/lexer.l
+++ b/source/adios2/toolkit/derived/parser/lexer.l
@@ -153,3 +153,9 @@ adios2::detail::ASTDriver::parse (const std::string input)
   parse.set_debug_level (trace_parsing);
   parse ();
 }
+
+void
+adios2::detail::ASTDriver::destroy_lex_structures ()
+{
+    yylex_destroy();
+}
diff --git a/source/adios2/toolkit/derived/parser/pregen-source/lexer.cpp b/source/adios2/toolkit/derived/parser/pregen-source/lexer.cpp
index 598731e63c..abc36e278f 100644
--- a/source/adios2/toolkit/derived/parser/pregen-source/lexer.cpp
+++ b/source/adios2/toolkit/derived/parser/pregen-source/lexer.cpp
@@ -1903,3 +1903,9 @@ adios2::detail::ASTDriver::parse (const std::string input)
   parse.set_debug_level (trace_parsing);
   parse ();
 }
+
+void
+adios2::detail::ASTDriver::destroy_lex_structures ()
+{
+    yylex_destroy();
+}