diff --git a/pluginlib/include/pluginlib/class_loader_imp.hpp b/pluginlib/include/pluginlib/class_loader_imp.hpp
index d45b5914..8951b9f3 100644
--- a/pluginlib/include/pluginlib/class_loader_imp.hpp
+++ b/pluginlib/include/pluginlib/class_loader_imp.hpp
@@ -319,7 +319,7 @@ std::vector<std::string> ClassLoader<T>::getCatkinLibraryPaths()
     boost::split(catkin_prefix_paths, env_catkin_prefix_paths, boost::is_any_of(os_pathsep));
     BOOST_FOREACH(std::string catkin_prefix_path, catkin_prefix_paths) {
       boost::filesystem::path path(catkin_prefix_path);
-#if _WIN32
+#ifdef _WIN32
       boost::filesystem::path bin("bin");
       lib_paths.push_back((path / bin).string());
 #endif