diff --git a/openbsc/src/system_information.c b/openbsc/src/system_information.c
index 6493794..42cd8ec 100644
--- a/openbsc/src/system_information.c
+++ b/openbsc/src/system_information.c
@@ -38,6 +38,22 @@
 #define GSM_MACBLOCK_LEN 		23
 #define GSM_MACBLOCK_PADDING		0x2b
 
+/* verify the sizes of the system information type structs */
+
+/* rest octets are not part of the struct */
+static_assert(sizeof(struct gsm48_system_information_type_header) == 3, _si_header_size);
+static_assert(sizeof(struct gsm48_rach_control) == 3, _si_rach_control);
+static_assert(sizeof(struct gsm48_system_information_type_1) == 22, _si1_size);
+static_assert(sizeof(struct gsm48_system_information_type_2) == 23, _si2_size);
+static_assert(sizeof(struct gsm48_system_information_type_3) == 19, _si3_size);
+static_assert(sizeof(struct gsm48_system_information_type_4) == 13, _si4_size);
+
+/* bs11 forgot the l2 len, 0-6 rest octets */
+static_assert(sizeof(struct gsm48_system_information_type_5) == 18, _si5_size);
+static_assert(sizeof(struct gsm48_system_information_type_6) == 11, _si6_size);
+
+static_assert(sizeof(struct gsm48_system_information_type_13) == 3, _si13_size);
+
 /* Frequency Lists as per TS 04.08 10.5.2.13 */
 
 /* 10.5.2.13.2: Bit map 0 format */