diff --git a/lib/wireshark_connector_impl.cc b/lib/wireshark_connector_impl.cc
index 54f7a7e..eff6b89 100644
--- a/lib/wireshark_connector_impl.cc
+++ b/lib/wireshark_connector_impl.cc
@@ -154,7 +154,10 @@ wireshark_connector_impl::general_work(int noutput, gr_vector_int& ninput_items,
 	gr_complex *out = (gr_complex*)output_items[0];
 
 	while(!d_msg_len) {
-		pmt::pmt_t msg(delete_head_blocking(pmt::mp("in")));
+		pmt::pmt_t msg = delete_head_nowait(pmt::mp("in"));
+		if(msg.get() == NULL) {
+			return 0;
+		}
 
 		if(pmt::is_eof_object(msg)) {
 			dout << "WIRESHARK: exiting" << std::endl;