diff -up ./tests/CMakeLists.txt.orig ./tests/CMakeLists.txt
--- ./tests/CMakeLists.txt.orig	2018-10-17 21:13:27.331580214 +0300
+++ ./tests/CMakeLists.txt	2018-10-17 21:15:18.095158010 +0300
@@ -26,6 +26,7 @@ else()
   find_package(Qt4 REQUIRED)
 endif()
 
+find_package(Threads REQUIRED)
 
 add_definitions(-DTEST_DATA_PATH="${CMAKE_CURRENT_SOURCE_DIR}")
 
@@ -61,7 +62,7 @@ if (QT4_FOUND OR Qt5Core_FOUND)
     add_test(bindingstest ${CMAKE_CURRENT_BINARY_DIR}/bindingstest)
 
     add_executable(conversiontest conversiontest.cpp ${CMAKE_CURRENT_BINARY_DIR}/${CONVERSIONTEST_MOC})
-    target_link_libraries(conversiontest ${QT_QTTEST_LIBRARY} ${QT_QTCORE_LIBRARY} kolabxml ${XERCES_C})
+    target_link_libraries(conversiontest Threads::Threads ${QT_QTTEST_LIBRARY} ${QT_QTCORE_LIBRARY} kolabxml ${XERCES_C})
     add_test(conversiontest ${CMAKE_CURRENT_BINARY_DIR}/conversiontest)
 
     add_executable(parsingtest parsingtest.cpp ${CMAKE_CURRENT_BINARY_DIR}/${PARSINGTEST_MOC})