diff --git a/src/box/key_def.cc b/src/box/key_def.cc
index 1c616ad1a9833d8101b357a33fdd37b76e6a49d7..16e9a92181d8f139e10bddd45a904e818faf40e3 100644
--- a/src/box/key_def.cc
+++ b/src/box/key_def.cc
@@ -59,6 +59,7 @@ const uint32_t key_mp_type[] = {
 	/* [FIELD_TYPE_SCALAR]   =  */ (1U << MP_UINT) | (1U << MP_INT) |
 		(1U << MP_FLOAT) | (1U << MP_DOUBLE) | (1U << MP_STR) |
 		(1U << MP_BIN) | (1U << MP_BOOL) | (1U << MP_NIL),
+	/* [FIELD_TYPE_MAP]      =  */ 1U << MP_MAP,
 };
 
 struct key_def *