diff --git a/srtcore/api.cpp b/srtcore/api.cpp
index 65760da61..fdf1c9d6d 100644
--- a/srtcore/api.cpp
+++ b/srtcore/api.cpp
@@ -2687,12 +2687,12 @@ int CUDT::epoll_uwait(
    {
       return s_UDTUnited.epoll_uwait(eid, fdsSet, fdsSize, msTimeOut);
    }
-   catch (CUDTException e)
+   catch (const CUDTException& e)
    {
       s_UDTUnited.setError(new CUDTException(e));
       return ERROR;
    }
-   catch (std::exception& ee)
+   catch (const std::exception& ee)
    {
       LOGC(mglog.Fatal, log << "epoll_uwait: UNEXPECTED EXCEPTION: "
          << typeid(ee).name() << ": " << ee.what());
@@ -2709,12 +2709,12 @@ int32_t CUDT::epoll_set(
    {
       return s_UDTUnited.epoll_set(eid, flags);
    }
-   catch (CUDTException e)
+   catch (const CUDTException& e)
    {
       s_UDTUnited.setError(new CUDTException(e));
       return ERROR;
    }
-   catch (std::exception& ee)
+   catch (const std::exception& ee)
    {
       LOGC(mglog.Fatal, log << "epoll_set: UNEXPECTED EXCEPTION: "
          << typeid(ee).name() << ": " << ee.what());