diff --git a/libs/EXTERNAL/libblifparse/CMakeLists.txt b/libs/EXTERNAL/libblifparse/CMakeLists.txt
index 57f33eb2e57..f38652308c8 100644
--- a/libs/EXTERNAL/libblifparse/CMakeLists.txt
+++ b/libs/EXTERNAL/libblifparse/CMakeLists.txt
@@ -13,7 +13,7 @@ if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
 endif()
 
 #Flex and Bison are used to generate the parser
-find_package(BISON REQUIRED 3.0)
+find_package(BISON REQUIRED 3.3)
 find_package(FLEX REQUIRED)
 
 file(GLOB_RECURSE LIB_SOURCES src/blif*.cpp)
diff --git a/libs/EXTERNAL/libblifparse/src/blif_parser.y b/libs/EXTERNAL/libblifparse/src/blif_parser.y
index 2b51dd7cc7e..495d495b6d8 100644
--- a/libs/EXTERNAL/libblifparse/src/blif_parser.y
+++ b/libs/EXTERNAL/libblifparse/src/blif_parser.y
@@ -1,5 +1,5 @@
-/* C++ parsers require Bison 3 */
-%require "3.0"
+/* C++ parsers require Bison 3.3 */
+%require "3.3"
 %language "C++"
 
 /* Write-out tokens header file */
@@ -34,7 +34,7 @@
 %define api.namespace {blifparse}
 
 /* Name the parser class */
-%define parser_class_name {Parser}
+%define api.parser.class {Parser}
 
 /* Match the flex prefix */
 %define api.prefix {blifparse_}
diff --git a/libs/EXTERNAL/libsdcparse/CMakeLists.txt b/libs/EXTERNAL/libsdcparse/CMakeLists.txt
index 24a7b2973c8..5afc97f3117 100644
--- a/libs/EXTERNAL/libsdcparse/CMakeLists.txt
+++ b/libs/EXTERNAL/libsdcparse/CMakeLists.txt
@@ -13,7 +13,7 @@ if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
 endif()
 
 #Flex and Bison are used to generate the parser
-find_package(BISON REQUIRED 3.0)
+find_package(BISON REQUIRED 3.3)
 find_package(FLEX REQUIRED)
 
 file(GLOB_RECURSE LIB_SOURCES src/sdc*.cpp)
diff --git a/libs/EXTERNAL/libsdcparse/src/sdc_parser.y b/libs/EXTERNAL/libsdcparse/src/sdc_parser.y
index 1dadaee3745..686173392bf 100644
--- a/libs/EXTERNAL/libsdcparse/src/sdc_parser.y
+++ b/libs/EXTERNAL/libsdcparse/src/sdc_parser.y
@@ -1,5 +1,5 @@
-/* C++ parsers require Bison 3 */
-%require "3.0"
+/* C++ parsers require Bison 3.3 */
+%require "3.3"
 %language "C++"
 
 /* Write-out tokens header file */
@@ -34,7 +34,7 @@
 %define api.namespace {sdcparse}
 
 /* Name the parser class */
-%define parser_class_name {Parser}
+%define api.parser.class {Parser}
 
 /* Match the flex prefix */
 %define api.prefix {sdcparse_}