diff --git a/src/os_unix.c b/src/os_unix.c
index 5d52a7f..0059d30 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -5787,7 +5787,9 @@
 	if (SETJMP(lc_jump_env) != 0)
 	{
 	    success = FALSE;
+#  if defined(USE_DLOPEN)
 	    dlerr = NULL;
+#  endif
 	    mch_didjmp();
 	}
 	else