diff --git a/library/GSM_SystemInformation.ttcn b/library/GSM_SystemInformation.ttcn
index 85abb7f..0356e7d 100644
--- a/library/GSM_SystemInformation.ttcn
+++ b/library/GSM_SystemInformation.ttcn
@@ -196,6 +196,11 @@
 		RestOctets			rest_octets length(0..7)
 	} with { variant "" };
 
+	/* 44.018 9.1.43a */
+	type record SystemInformationType13 {
+		SI13RestOctets			rest_octets
+	} with { variant "" };
+
 	type union SystemInformationUnion {
 		SystemInformationType1		si1,
 		SystemInformationType2		si2,
@@ -208,6 +213,7 @@
 		SystemInformationType5bis	si5bis,
 		SystemInformationType5ter	si5ter,
 		SystemInformationType6		si6,
+		SystemInformationType13		si13,
 		octetstring			other
 	} with { variant "" };
 
@@ -225,6 +231,7 @@
 			      si5bis, header.message_type = SYSTEM_INFORMATION_TYPE_5bis;
 			      si5ter, header.message_type = SYSTEM_INFORMATION_TYPE_5ter;
 			      si6, header.message_type = SYSTEM_INFORMATION_TYPE_6;
+			      si13, header.message_type = SYSTEM_INFORMATION_TYPE_13;
 			      other, OTHERWISE;
 			)" };