diff --git a/tool/CMakeLists.txt b/tool/CMakeLists.txt
index 79077455..2d706baf 100644
--- a/tool/CMakeLists.txt
+++ b/tool/CMakeLists.txt
@@ -19,5 +19,10 @@ add_executable(
 if (APPLE OR WIN32 OR ANDROID)
   target_link_libraries(bssl ssl crypto)
 else()
-  target_link_libraries(bssl ssl crypto -lrt)
+  find_library(FOUND_LIBRT rt)
+  if (FOUND_LIBRT)
+    target_link_libraries(bssl ssl crypto -lrt)
+  else()
+    target_link_libraries(bssl ssl crypto)
+  endif()
 endif()