diff --git a/openbsc/src/libbsc/abis_rsl.c b/openbsc/src/libbsc/abis_rsl.c
index d750df4..85c92cd 100644
--- a/openbsc/src/libbsc/abis_rsl.c
+++ b/openbsc/src/libbsc/abis_rsl.c
@@ -2018,7 +2018,7 @@
 		/* FIXME: Replace the messy message parsing below
 		 * with proper TV parser */
 		LOGP(DRSL, LOGL_INFO, "IMM.ass sent\n");
-		if(msg->len < 8)
+		if(msg->len < 9)
 			LOGP(DRSL, LOGL_ERROR, "short IMM.ass sent message!\n");
 		else if(msg->data[4] != 0xf1)
 			LOGP(DRSL, LOGL_ERROR, "unsupported IMM.ass message format! (please fix)\n");