diff --git a/libdap-cuttdb/src/cdb_bgtask.c b/libdap-cuttdb/src/cdb_bgtask.c
index 822c02c1299c1f03fd5b738f50183e474dffce0a..da998c2b0a0f164350186c74e1bed80f95f5d633 100644
--- a/libdap-cuttdb/src/cdb_bgtask.c
+++ b/libdap-cuttdb/src/cdb_bgtask.c
@@ -61,7 +61,7 @@ static void *_cdb_bgtask_func(void *arg)
     CDBBGTASK *bt = (CDBBGTASK *)arg;
 #ifndef _WIN32
     /* block all signals coming into current thread */
-    _sigset_t smask;
+    sigset_t smask;
     sigfillset(&smask);
     pthread_sigmask(SIG_BLOCK, &smask, NULL);
 #endif