diff --git a/CMakeLists.txt b/CMakeLists.txt
index 702ef7e7f..6c8b0795e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,6 +5,8 @@ project(Algorithms_in_C
     DESCRIPTION "Set of algorithms implemented in C."
 )
 
+option(USE_OPENMP "flag to use OpenMP for multithreading" ON)
+
 add_subdirectory(function_timer EXCLUDE_FROM_ALL)
 include_directories(function_timer/include)
 # link_libraries(function_timer)
@@ -13,8 +15,11 @@ include_directories(function_timer/include)
 
 add_subdirectory(conversions)
 add_subdirectory(misc)
+add_subdirectory(project_euler)
 
-find_package(OpenMP)
+if(USE_OPENMP)
+    find_package(OpenMP)
+endif()
 
 set(CPACK_PROJECT_NAME ${PROJECT_NAME})
 set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
diff --git a/project_euler/CMakeLists.txt b/project_euler/CMakeLists.txt
index 234069e8a..abb40df59 100644
--- a/project_euler/CMakeLists.txt
+++ b/project_euler/CMakeLists.txt
@@ -1,3 +1,7 @@
+if(USE_OPENMP)
+    find_package(OpenMP)
+endif()
+
 # If necessary, use the RELATIVE flag, otherwise each source file may be listed
 # with full pathname. RELATIVE may makes it easier to extract an executable name
 # automatically.