make tests conditional
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3aa8122..6d1bf51 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,8 +5,9 @@ cmake_minimum_required(VERSION 3.10.0 FATAL_ERROR)
 #set( CMAKE_CXX_STANDARD_REQUIRED TRUE )
 #set( CMAKE_CXX_STANDARD 11 )
 
-enable_testing()
-
+if(OPENMESH_BUILD_UNIT_TESTS)
+  enable_testing()
+endif()
 
 project (OpenMesh 
          VERSION 11.0.0
@@ -118,7 +119,9 @@ endif()
 
 # Do not build unit tests when build as external library
 if(${CMAKE_PROJECT_NAME} MATCHES "OpenMesh")
+  if(OPENMESH_BUILD_UNIT_TESTS)
     add_subdirectory (src/Unittests)
+  endif()
 else()
 	# If built as a dependent project simulate effects of
 	# successful finder run: