diff --git a/openair2/LAYER2/nr_rlc/nr_rlc_entity_am.c b/openair2/LAYER2/nr_rlc/nr_rlc_entity_am.c
index e1ae1df077..804f1e8a74 100644
--- a/openair2/LAYER2/nr_rlc/nr_rlc_entity_am.c
+++ b/openair2/LAYER2/nr_rlc/nr_rlc_entity_am.c
@@ -1285,7 +1285,7 @@ static int missing_size(nr_rlc_entity_am_t *entity, missing_data_t *m,
   missing_data_t m_nack;
 
   /* be careful to limit a range to 255 SNs, that is: cut if needed */
-  sn_count = m->sn_end - m->sn_start;
+  sn_count = m->sn_end - m->sn_start + 1;
   if (sn_count < 0)
     sn_count += entity->sn_modulus;
 
diff --git a/openair2/LAYER2/nr_rlc/tests/run_tests.sh b/openair2/LAYER2/nr_rlc/tests/run_tests.sh
index ac22516064..bf1b343d7e 100755
--- a/openair2/LAYER2/nr_rlc/tests/run_tests.sh
+++ b/openair2/LAYER2/nr_rlc/tests/run_tests.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-test_count=13
+test_count=14
 
 for i in `seq $test_count`
 do
diff --git a/openair2/LAYER2/nr_rlc/tests/test14.h b/openair2/LAYER2/nr_rlc/tests/test14.h
new file mode 100644
index 0000000000..9eb472b270
--- /dev/null
+++ b/openair2/LAYER2/nr_rlc/tests/test14.h
@@ -0,0 +1,46 @@
+/*
+ * am test (SN field size 18):
+ * test status reporting with missing packet
+ * at time 1, UE receives an SDU of 50 bytes
+ * at time 2, UE receives an SDU of 50 bytes
+ * at time 3, UE receives an SDU of 50 bytes
+ * at time 4, UE receives an SDU of 50 bytes
+ * transmission fails for first SDU, okay for the others
+ * then some time with transmission failing
+ * then at time 49, UE receives an SDU, transmission okay
+ * then at time 50, transmission failing again (we had a bug triggered by this)
+ * finally at time 55, transmission okay again to clear buffers
+ */
+
+TIME, 1,
+    GNB_AM, 100000, 100000, 45, 35, 0, -1, -1, 8, 18,
+    UE_AM, 100000, 100000, 45, 35, 0, -1, -1, 8, 18,
+    GNB_RECV_FAILS, 1,
+    GNB_PDU_SIZE, 80,
+    UE_PDU_SIZE, 80,
+    UE_SDU, 0, 50,
+TIME, 2,
+    GNB_RECV_FAILS, 0,
+    UE_SDU, 1, 50,
+TIME, 3,
+    GNB_BUFFER_STATUS,
+    UE_SDU, 2, 50,
+TIME, 4,
+    GNB_BUFFER_STATUS,
+    UE_SDU, 3, 50,
+TIME, 5,
+    GNB_BUFFER_STATUS,
+    GNB_RECV_FAILS, 1,
+TIME, 6,
+    GNB_BUFFER_STATUS,
+    UE_BUFFER_STATUS,
+TIME, 49,
+    GNB_RECV_FAILS, 0,
+    UE_SDU, 4, 50,
+TIME, 50,
+    GNB_RECV_FAILS, 1,
+    GNB_BUFFER_STATUS,
+    UE_BUFFER_STATUS,
+TIME, 55,
+    GNB_RECV_FAILS, 0,
+TIME, -1
diff --git a/openair2/LAYER2/nr_rlc/tests/test14.txt.gz b/openair2/LAYER2/nr_rlc/tests/test14.txt.gz
new file mode 100644
index 0000000000..7ab2fc3431
Binary files /dev/null and b/openair2/LAYER2/nr_rlc/tests/test14.txt.gz differ