diff --git a/Modules/FindProtobuf.cmake b/Modules/FindProtobuf.cmake
index f6d8fe3100..4bf54efe3c 100644
--- a/Modules/FindProtobuf.cmake
+++ b/Modules/FindProtobuf.cmake
@@ -388,7 +388,7 @@ function(_protobuf_find_libraries name filename)
 
     select_library_configurations(${name})
 
-    if(UNIX AND Threads_FOUND)
+    if(UNIX AND Threads_FOUND AND ${name}_LIBRARY)
       list(APPEND ${name}_LIBRARIES ${CMAKE_THREAD_LIBS_INIT})
     endif()