diff --git a/src/box/tuple_format.c b/src/box/tuple_format.c
index 9b913306449563a471cd743a9e17cb4f6634541a..02fadf1cf63a31ce3d079602352a33ba2c17dd09 100644
--- a/src/box/tuple_format.c
+++ b/src/box/tuple_format.c
@@ -1138,7 +1138,6 @@ tuple_format_iterator_next(struct tuple_format_iterator *it,
 			 * and is equal to multikey index
 			 * comparison hint.
 			 */
-			assert(type == MP_ARRAY);
 			it->multikey_frame = mp_stack_top(&it->stack);
 		}
 		it->parent = &field->token;
diff --git a/test/engine/multikey.result b/test/engine/multikey.result
index e7326cb96a2af92560762d260e3ab53a6893d85e..30208227080095533e70b65dc8537b4be4fad6f0 100644
--- a/test/engine/multikey.result
+++ b/test/engine/multikey.result
@@ -835,3 +835,31 @@ s.index.sk:select()
 s:drop()
 ---
 ...
+--
+-- Inserting a map where a multikey array is expected is
+-- handled gracefully: no crashes, just an error message.
+--
+s = box.schema.space.create('test', {engine = engine})
+---
+...
+_ = s:create_index('pk')
+---
+...
+_ = s:create_index('sk', {parts = {{'[2][*]', 'unsigned'}}})
+---
+...
+s:insert{1, {a = 1}} -- error
+---
+- error: 'Tuple field 2 type does not match one required by operation: expected array'
+...
+s:insert{2, {1}} -- ok
+---
+- [2, [1]]
+...
+s.index.sk:select()
+---
+- - [2, [1]]
+...
+s:drop()
+---
+...
diff --git a/test/engine/multikey.test.lua b/test/engine/multikey.test.lua
index 48eed2a3b055ef6c9ef387047375a1620088d969..6d974716acc7ba601a04dc79a080282fb7622a21 100644
--- a/test/engine/multikey.test.lua
+++ b/test/engine/multikey.test.lua
@@ -224,3 +224,15 @@ s:insert{7, {}} -- ok
 s:insert{8, {2}} -- ok
 s.index.sk:select()
 s:drop()
+
+--
+-- Inserting a map where a multikey array is expected is
+-- handled gracefully: no crashes, just an error message.
+--
+s = box.schema.space.create('test', {engine = engine})
+_ = s:create_index('pk')
+_ = s:create_index('sk', {parts = {{'[2][*]', 'unsigned'}}})
+s:insert{1, {a = 1}} -- error
+s:insert{2, {1}} -- ok
+s.index.sk:select()
+s:drop()