Index: ykcs11/CMakeLists.txt
--- ykcs11/CMakeLists.txt.orig
+++ ykcs11/CMakeLists.txt
@@ -73,7 +73,7 @@ endif(BUILD_STATIC_LIB)
 
 # dynamic library
 add_library(ykcs11_shared SHARED ${SOURCE})
-target_link_libraries(ykcs11_shared ${LIBCRYPTO_LDFLAGS} ykpiv_shared)
+target_link_libraries(ykcs11_shared ${LIBCRYPTO_LDFLAGS} ykpiv_shared pthread)
 set_target_properties(ykcs11_shared PROPERTIES SOVERSION ${SO_VERSION} VERSION ${VERSION})
 if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
     set_target_properties(ykcs11_shared PROPERTIES INSTALL_RPATH "${YKPIV_INSTALL_LIB_DIR}")
