diff --git a/src/box/lua/error.cc b/src/box/lua/error.cc
index 08c2d983dd4dd8328d56b998356c8c8e1a9f02b4..b2625bf5f309ae04686086b5e68312546fbad0b2 100644
--- a/src/box/lua/error.cc
+++ b/src/box/lua/error.cc
@@ -114,9 +114,16 @@ luaT_error_call(lua_State *L)
 			return luaT_error(L);
 		return 0;
 	}
-	if (lua_gettop(L) == 2 && luaL_iserror(L, 2))
-		return lua_error(L);
-	struct error *e = luaT_error_create(L, 2);
+	struct error *e = NULL;
+	if (lua_gettop(L) == 2) {
+		e = luaL_iserror(L, 2);
+		if (e != NULL) {
+			/* Re-set error to diag area. */
+			diag_set_error(&fiber()->diag, e);
+			return lua_error(L);
+		}
+	}
+	e = luaT_error_create(L, 2);
 	if (e == NULL)
 		return luaL_error(L, "box.error(): bad arguments");
 	diag_set_error(&fiber()->diag, e);
diff --git a/test/box/error.result b/test/box/error.result
index 3d07f6e64c1a2aa342e0bfc5e59801c656668262..234c26371de3b54a79a7d06c8e64ac86559b91f0 100644
--- a/test/box/error.result
+++ b/test/box/error.result
@@ -808,3 +808,25 @@ assert(e2.prev == e3)
  | ---
  | - true
  | ...
+
+-- gh-4829: always promote error created via box.error() to
+-- diagnostic area.
+e1 = box.error.new({code = 111, reason = "cause"})
+ | ---
+ | ...
+box.error({code = 111, reason = "err"})
+ | ---
+ | - error: err
+ | ...
+box.error.last()
+ | ---
+ | - err
+ | ...
+box.error(e1)
+ | ---
+ | - error: cause
+ | ...
+assert(box.error.last() == e1)
+ | ---
+ | - true
+ | ...
diff --git a/test/box/error.test.lua b/test/box/error.test.lua
index ed7eb7565498bac9b8c0e8d30b47016883b99705..41baed52d24614e5d0d365a198a0dc723ca7bbc7 100644
--- a/test/box/error.test.lua
+++ b/test/box/error.test.lua
@@ -221,3 +221,11 @@ e2:set_prev(e3)
 box.error.set(e2)
 assert(e1.prev == nil)
 assert(e2.prev == e3)
+
+-- gh-4829: always promote error created via box.error() to
+-- diagnostic area.
+e1 = box.error.new({code = 111, reason = "cause"})
+box.error({code = 111, reason = "err"})
+box.error.last()
+box.error(e1)
+assert(box.error.last() == e1)