diff --git a/library/BSSGP_Emulation.ttcnpp b/library/BSSGP_Emulation.ttcnpp
index 1b628b3..d01c7a2 100644
--- a/library/BSSGP_Emulation.ttcnpp
+++ b/library/BSSGP_Emulation.ttcnpp
@@ -1115,10 +1115,10 @@
 		f_ptp_change_state(BVC_S_BLOCKED);
 	}
 	/* Re-transmit BLOCK / UNBLOCK on T1 timeout */
-	[not g_t1_waits_for_block_ack] g_T1.timeout {
+	[g_T1.running and not g_t1_waits_for_block_ack] g_T1.timeout {
 		f_ptp_sendUnblock();
 	}
-	[g_t1_waits_for_block_ack] g_T1.timeout {
+	[g_T1.running and g_t1_waits_for_block_ack] g_T1.timeout {
 		f_ptp_sendBlock(g_last_block_cause);
 	}