diff --git a/tool/CMakeLists.txt b/tool/CMakeLists.txt
index 4bb6ca2..74c1ac8 100644
--- a/tool/CMakeLists.txt
+++ b/tool/CMakeLists.txt
@@ -15,4 +15,8 @@
   transport_common.cc
 )
 
-target_link_libraries(bssl ssl crypto)
+if (APPLE OR WIN32 OR ANDROID)
+  target_link_libraries(bssl ssl crypto)
+else()
+  target_link_libraries(bssl ssl crypto -lrt)
+endif()