diff --git a/hw3-heat-fft/CMakeLists.txt b/hw3-heat-fft/CMakeLists.txt
index 8d4c0991..ed7ededc 100644
--- a/hw3-heat-fft/CMakeLists.txt
+++ b/hw3-heat-fft/CMakeLists.txt
@@ -1,81 +1,93 @@
 cmake_minimum_required (VERSION 3.1)
 project (Particles)
 cmake_policy(VERSION 3.3)
 
 set(CMAKE_CXX_STANDARD 14)
 
+option (USE_FFTW "Use FFTW part of the code" ON)
+
 ###############################################################
 # Include FFTW library and header files
 ###############################################################
 
-# Not the most elegant way
-set(FFTW_LIBRARIES "/usr/lib/x86_64-linux-gnu/libfftw3.so")
-set(FFTW_INCLUDES "/usr/include")
+if (USE_FFTW)
+	# Not the most elegant way, but it works!
+	set(FFTW_LIBRARIES "/usr/lib/x86_64-linux-gnu/libfftw3.so")
+	set(FFTW_INCLUDES "/usr/include")
+
+	# Alternative way that does not currently work:
+	#set(FFTW_LIBRARIES CACHE PATH "library where to search libfftw3")
+	#find_library(FFTW_LIBRARY libfftw3 ${FFTW_LIBRARIES} /usr/lib)
+	#set(FFTW_INCLUDES CACHE PATH "path where to search fftw include files")
+	#find_path(FFTW_INCLUDE fftw3.h ${FFTW_INCLUDES} /usr/include/)
 
-# Alternative way that does not currently work:
-#set(FFTW_LIBRARIES CACHE PATH "library where to search libfftw3")
-#find_library(FFTW_LIBRARY libfftw3 ${FFTW_LIBRARIES} /usr/lib)
-#set(FFTW_INCLUDES CACHE PATH "path where to search fftw include files")
-#find_path(FFTW_INCLUDE fftw3.h ${FFTW_INCLUDES} /usr/include/)
+	include_directories("${FFTW_INCLUDES}")
 
-include_directories("${FFTW_INCLUDES}")
-message("FFTW_LIBRARIES = ${FFTW_LIBRARIES}")
-message("FFTW_INCLUDES = ${FFTW_INCLUDES}")
+	message("FFTW_LIBRARIES = ${FFTW_LIBRARIES}")
+	message("FFTW_INCLUDES = ${FFTW_INCLUDES}")
+endif(USE_FFTW)
 
 ################################################################
 # libpart
 ################################################################
 
 add_library(part
   compute_boundary.cc
   compute_verlet_integration.cc 
   particle.cc 
   planet.cc
   compute_gravity.cc 
   csv_reader.cc 
   particles_factory_interface.cc 
   planets_factory.cc 
   compute_contact.cc 
   compute_kinetic_energy.cc 
   csv_writer.cc 
   system.cc 
   compute_energy.cc 
   compute_potential_energy.cc 
   ping_pong_ball.cc
   material_point.cc 
   system_evolution.cc 
   ping_pong_balls_factory.cc 
   compute_interaction.cc
   compute_temperature.cc
   material_points_factory.cc 
   )
 
 add_executable(particles main.cc)
 target_link_libraries(particles part)
 
 ################################################################
 # Google test
 ################################################################
 
 add_subdirectory(googletest)
 
 add_executable(test_kepler test_kepler.cc)
-add_executable(test_fft test_fft.cc)
+
+if (USE_FFTW)
+	add_executable(test_fft test_fft.cc)
+endif(USE_FFTW)
+
 target_link_libraries(test_kepler part gtest_main gtest pthread)
-target_link_libraries(test_fft part gtest_main gtest ${FFTW_LIBRARIES} pthread)
+
+if (USE_FFTW)
+	target_link_libraries(test_fft part gtest_main gtest ${FFTW_LIBRARIES} pthread)
+endif(USE_FFTW)
 
 ################################################################
 # Doxygen
 ################################################################
 
 find_package(Doxygen)
 if (DOXYGEN_FOUND)
 
 # to set other options, read: https://cmake.org/cmake/help/v3.9/module/FindDoxygen.html
 doxygen_add_docs(
     doxygen
     ${PROJECT_SOURCE_DIR}
     COMMENT "Generate html pages"
 )
 add_custom_target(doc DEPENDS doxygen)
 endif(DOXYGEN_FOUND)