diff --git a/src/box/iproto.cc b/src/box/iproto.cc
index 5dfb2b83fd7d4c7abdc585471100cff755b37656..8876acb8d5e2684543c4982bdd5c4ae1d58bfdf2 100644
--- a/src/box/iproto.cc
+++ b/src/box/iproto.cc
@@ -914,6 +914,7 @@ static const struct cmsg_hop *dml_route[IPROTO_TYPE_STAT_MAX] = {
 	call_route,                             /* IPROTO_EVAL */
 	process1_route,                         /* IPROTO_UPSERT */
 	call_route,                             /* IPROTO_CALL */
+	NULL,                                   /* reserved */
 	NULL,                                   /* IPROTO_NOP */
 };
 
diff --git a/src/box/iproto_constants.c b/src/box/iproto_constants.c
index 7710196da807bb19f21180ee31bc77dab1179cb4..cd7b1d03bc6e5504b21ae96c6c5863a09352d05b 100644
--- a/src/box/iproto_constants.c
+++ b/src/box/iproto_constants.c
@@ -102,6 +102,7 @@ const char *iproto_type_strs[] =
 	"EVAL",
 	"UPSERT",
 	"CALL",
+	NULL, /* reserved */
 	NULL, /* NOP */
 };
 
@@ -118,6 +119,7 @@ const uint64_t iproto_body_key_map[IPROTO_TYPE_STAT_MAX] = {
 	0,                                                     /* EVAL */
 	bit(SPACE_ID) | bit(OPS) | bit(TUPLE),                 /* UPSERT */
 	0,                                                     /* CALL */
+	0,                                                     /* reserved */
 	bit(SPACE_ID),                                         /* NOP */
 };
 #undef bit
diff --git a/src/box/iproto_constants.h b/src/box/iproto_constants.h
index 94b111ad9617d7054998ae21d7a1106b0223047c..b0964124ab54f3a19a151a62cb376c6499ed1b47 100644
--- a/src/box/iproto_constants.h
+++ b/src/box/iproto_constants.h
@@ -141,8 +141,9 @@ enum iproto_type {
 	IPROTO_UPSERT = 9,
 	/** CALL request - returns arbitrary MessagePack */
 	IPROTO_CALL = 10,
+	/* 11 is reserved for SQL */
 	/** No operation. Treated as DML, used to bump LSN. */
-	IPROTO_NOP = 11,
+	IPROTO_NOP = 12,
 	/** The maximum typecode used for box.stat() */
 	IPROTO_TYPE_STAT_MAX,