diff --git a/CMakeLists.txt b/CMakeLists.txt
index e49b60532d..3e617f871f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -92,10 +92,16 @@ endif()
 set_property(GLOBAL PROPERTY CTEST_TARGETS_ADDED 1)
 include(CTest)
 
-# By default only build the C++ library.
+# By default only build the C++ library which agregate all components.
 option(BUILD_CXX "Build C++ library" ON)
 message(STATUS "Build C++ library: ${BUILD_CXX}")
 
+# If we don't build ortools we could build the GLOP standalone project
+if(NOT BUILD_CXX)
+  OPTION(BUILD_GLOP "Build GLOP standalone" ON)
+  message(STATUS "Build standalone Glop: ${BUILD_GLOP}")
+endif()
+
 option(BUILD_PYTHON "Build Python Library" OFF)
 message(STATUS "Build Python: ${BUILD_PYTHON}")
 option(BUILD_JAVA "Build Java Library" OFF)
@@ -123,9 +129,6 @@ message(STATUS "Build LP Parser: ${BUILD_LP_PARSER}")
 CMAKE_DEPENDENT_OPTION(BUILD_MATH_OPT "Build the MATH_OPT" ON "BUILD_CXX" OFF)
 message(STATUS "Build MathOpt: ${BUILD_MATH_OPT}")
 
-CMAKE_DEPENDENT_OPTION(BUILD_GLOP "Build GLOP standalone" ON "NOT BUILD_CXX" OFF)
-message(STATUS "Build standalone Glop: ${BUILD_GLOP}")
-
 ## Samples
 option(BUILD_SAMPLES "Build samples" ON)
 message(STATUS "Build samples: ${BUILD_SAMPLES}")
@@ -198,6 +201,11 @@ else()
 endif()
 
 # Optional third party solvers (enabled by default)
+## BOP
+# note OFF is currently not supported.
+CMAKE_DEPENDENT_OPTION(USE_BOP "Use the BOP solver" ON "BUILD_CXX" OFF)
+message(STATUS "BOP support: ${USE_BOP}")
+
 ## COIN-OR Solvers (Cbc, Clp)
 CMAKE_DEPENDENT_OPTION(USE_COINOR "Use the COIN-OR solver" ON "BUILD_CXX" OFF)
 message(STATUS "COIN-OR support: ${USE_COINOR}")
@@ -223,6 +231,11 @@ if(USE_COINOR)
   message(STATUS "Build Cbc: ${BUILD_Cbc}")
 endif()
 
+## GLOP
+# note OFF is currently not supported.
+CMAKE_DEPENDENT_OPTION(USE_GLOP "Use the GLOP solver" ON "BUILD_CXX" OFF)
+message(STATUS "GLOP support: ${USE_GLOP}")
+
 ## GLPK
 # Disable by default since it is GPLv3, user could enable it and release under GPLv3
 # see: https://www.apache.org/licenses/GPL-compatibility.html
diff --git a/cmake/cpp.cmake b/cmake/cpp.cmake
index 64d0a59712..82221b1c4d 100644
--- a/cmake/cpp.cmake
+++ b/cmake/cpp.cmake
@@ -25,11 +25,6 @@ set(OR_TOOLS_LINK_OPTIONS)
 if(BUILD_SHARED_LIBS)
   list(APPEND OR_TOOLS_COMPILE_DEFINITIONS "OR_TOOLS_AS_DYNAMIC_LIB")
 endif()
-# Mandatory built-in components
-list(APPEND OR_TOOLS_COMPILE_DEFINITIONS
-  "USE_BOP" # enable BOP support
-  "USE_GLOP" # enable GLOP support
-  )
 # Optional built-in components
 if(BUILD_LP_PARSER)
   list(APPEND OR_TOOLS_COMPILE_DEFINITIONS "USE_LP_PARSER")
@@ -39,12 +34,18 @@ if(BUILD_MATH_OPT)
   set(MATH_OPT_DIR math_opt)
 endif()
 # Optional solvers
+if(USE_BOP)
+  list(APPEND OR_TOOLS_COMPILE_DEFINITIONS "USE_BOP")
+endif()
 if(USE_COINOR)
   list(APPEND OR_TOOLS_COMPILE_DEFINITIONS
     "USE_CBC" # enable COIN-OR CBC support
     "USE_CLP" # enable COIN-OR CLP support
   )
 endif()
+if(USE_GLOP)
+  list(APPEND OR_TOOLS_COMPILE_DEFINITIONS "USE_GLOP")
+endif()
 if(USE_GLPK)
   list(APPEND OR_TOOLS_COMPILE_DEFINITIONS "USE_GLPK")
   set(GLPK_DIR glpk)