diff --git a/src/def/CMakeLists.txt b/src/def/CMakeLists.txt
index ee1ccfe2..de08717a 100644
--- a/src/def/CMakeLists.txt
+++ b/src/def/CMakeLists.txt
@@ -3,8 +3,6 @@ project(DEF_PARSER
   LANGUAGES CXX 
 )
 
-cmake_minimum_required(VERSION 3.1)
-
 set(DEFLIB_HOME ${CMAKE_CURRENT_SOURCE_DIR})
 
 # BISON and ZLIB is required to compile DEF/LEF Parsers.
diff --git a/src/lef/CMakeLists.txt b/src/lef/CMakeLists.txt
index ee9cc663..67552bad 100644
--- a/src/lef/CMakeLists.txt
+++ b/src/lef/CMakeLists.txt
@@ -3,8 +3,6 @@ project(LEF_PARSER
   LANGUAGES CXX 
 )
 
-cmake_minimum_required(VERSION 2.6)
-
 set(LEFLIB_HOME ${CMAKE_CURRENT_SOURCE_DIR})
 message(STATUS "leflib_home: ${LEFLIB_HOME}")