diff --git a/CMakeLists.txt b/CMakeLists.txt
index 21f8b28a1..52b34101f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,12 +6,6 @@ if(NOT DEFINED CMAKE_MACOSX_RPATH)
   set(CMAKE_MACOSX_RPATH 0)
 endif()
 
-option(GTSAM_NO_BOOST_CPP17 "Require and use boost" ON)
-
-if (GTSAM_NO_BOOST_CPP17)
-  set(CMAKE_CXX_STANDARD 17)
-endif()
-
 # Set the version number for the library
 set (GTSAM_VERSION_MAJOR 4)
 set (GTSAM_VERSION_MINOR 3)
@@ -57,11 +51,7 @@ endif()
 include(cmake/HandleGeneralOptions.cmake)   # CMake build options
 
 # Libraries:
-if (GTSAM_NO_BOOST_CPP17)
-  include(cmake/HandleBoost.cmake)            # Boost
-  add_definitions(-DNO_BOOST_CPP17)
-endif()
-  
+include(cmake/HandleBoost.cmake)            # Boost
 include(cmake/HandleCCache.cmake)           # ccache
 include(cmake/HandleCPack.cmake)            # CPack
 include(cmake/HandleEigen.cmake)            # Eigen3