diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index e0e8ac4..e98a8ca 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -669,7 +669,9 @@
 
 	/* default max-ta is 63 (full range of GSM timing advance */
 
-	/* negative TA must not happen */
+	/* We allow early arrival up to 2 symbols */
+	f_rach_toffs(-1*256, true);
+	f_rach_toffs(-2*256, true);
 	f_rach_toffs(-10*256, false);
 
 	/* 0 / 32 / 63 bits is legal / permitted */