diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn
index b381893c6..1d2a14853 100644
--- a/bts/BTS_Tests.ttcn
+++ b/bts/BTS_Tests.ttcn
@@ -3674,7 +3674,8 @@ private function f_si_vecslot_contains_n_of_m(SystemInformationVector arr,
 return boolean {
 	var integer count := 0;
 	if (sizeof(arr) < m) {
-		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, "Error: Insufficient SI in array");
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, "Error: Insufficient SI in array: "
+					& int2str(sizeof(arr)) & " < " & int2str(m));
 	}
 	for (var integer i:= 0; i < m; i := i + 1) {
 		var integer fn_mod51 := arr[i].frame_number mod 51;