diff --git a/src/lj_parse.c b/src/lj_parse.c
index af0dc53fa6..343fa797c3 100644
--- a/src/lj_parse.c
+++ b/src/lj_parse.c
@@ -1546,7 +1546,7 @@ static void fs_fixup_ret(FuncState *fs)
 	/* Replace with UCLO plus branch. */
 	fs->bcbase[pc].ins = BCINS_AD(BC_UCLO, 0, offset);
 	break;
-      case BC_UCLO:
+      case BC_FNEW:
 	return;  /* We're done. */
       default:
 	break;
diff --git a/test/tarantool-tests/lj-819-fix-missing-uclo.test.lua b/test/tarantool-tests/lj-819-fix-missing-uclo.test.lua
new file mode 100644
index 0000000000..942c22b2a4
--- /dev/null
+++ b/test/tarantool-tests/lj-819-fix-missing-uclo.test.lua
@@ -0,0 +1,115 @@
+local tap = require('tap')
+-- Test contains a reproducer for a problem when LuaJIT generates a wrong
+-- bytecode with a missed BC_UCLO instruction.
+local test = tap.test('lj-819-fix-missing-uclo'):skipcond({
+  ['Test requires JIT enabled'] = not jit.status(),
+})
+
+test:plan(2)
+
+-- Let's take a look at listings Listing 1 and Listing 2 below with bytecode
+-- generated for a function missing_uclo() with and without a patch.
+-- Both listings contains two BC_UCLO instructions:
+-- - first one with id 0004 is generated for a statement 'break' inside
+--   condition, see label BC_UCLO1;
+-- - second one with id 0009 is generated for a statement 'return' inside
+--   a nested loop, see label BC_UCLO2;
+-- Both BC_UCLO's closes upvalues after leaving a function's scope.
+--
+-- The problem is happen when fs_fixup_ret() traverses bytecode instructions in
+-- a function prototype, meets first BC_UCLO instruction (break) and forgives a
+-- second one (return). This leads to a wrong result produced by a function
+-- returned by missing_uclo() function. This also explains why do we need a
+-- dead code in reproducer - without first BC_UCLO fs_fixup_ret() successfully
+-- fixup BC_UCLO and problem does not appear.
+--
+-- Listing 1. Bytecode with a fix.
+--
+-- -- BYTECODE -- uclo.lua:1-59
+-- 0001 => LOOP     0 => 0013
+-- 0002    JMP      0 => 0003
+-- 0003 => JMP      0 => 0005
+-- 0004    UCLO     0 => 0013
+-- 0005 => KPRI     0   0
+-- 0006 => LOOP     1 => 0012
+-- 0007    ISF          0
+-- 0008    JMP      1 => 0010
+-- 0009    UCLO     0 => 0014
+-- 0010 => FNEW     0   0      ; uclo.lua:54
+-- 0011    JMP      1 => 0006
+-- 0012 => UCLO     0 => 0001
+-- 0013 => RET0     0   1
+-- 0014 => RET1     0   2
+--
+-- Listing 2. Bytecode without a fix.
+--
+-- BYTECODE -- uclo.lua:1-59
+-- 0001 => LOOP     0 => 0013
+-- 0002    JMP      0 => 0003
+-- 0003 => JMP      0 => 0005
+-- 0004    UCLO     0 => 0013
+-- 0005 => KPRI     0   0
+-- 0006 => LOOP     1 => 0012
+-- 0007    ISF          0
+-- 0008    JMP      1 => 0010
+-- 0009    UCLO     0 => 0014
+-- 0010 => FNEW     0   0      ; uclo.lua:54
+-- 0011    JMP      1 => 0006
+-- 0012 => UCLO     0 => 0001
+-- 0013 => RET0     0   1
+-- 0014 => RET1     0   2
+--
+-- Listing 3. Changes in bytecode before and after a fix.
+--
+-- @@ -11,11 +11,12 @@
+--  0006 => LOOP     1 => 0012
+--  0007    ISF          0
+--  0008    JMP      1 => 0010
+-- -0009    RET1     0   2
+-- +0009    UCLO     0 => 0014
+--  0010 => FNEW     0   0      ; uclo.lua:56
+--  0011    JMP      1 => 0006
+--  0012 => UCLO     0 => 0001
+--  0013 => RET0     0   1
+-- +0014 => RET1     0   2
+--
+-- First testcase checks a correct bytecode generation by frontend
+-- and the second testcase checks consistency on a JIT compilation.
+
+local function missing_uclo()
+  while true do -- luacheck: ignore
+    -- Attention: it is not a dead code, it is a part of reproducer.
+    -- label: BC_UCLO1
+    if false then
+      break
+    end
+    local f
+    while true do
+      if f then
+        -- label: BC_UCLO2
+        return f
+      end
+      f = function()
+        return f
+      end
+    end
+  end
+end
+
+local f = missing_uclo()
+local res = f()
+-- Without a patch we don't get here a function, because upvalue isn't closed
+-- as desirable.
+test:ok(type(res) == 'function', 'virtual machine consistency: type of returned value is correct')
+
+-- Make JIT compiler aggressive.
+jit.opt.start('hotloop=1')
+
+f = missing_uclo()
+f()
+f = missing_uclo()
+local _
+_, res = pcall(f)
+test:ok(type(res) == 'function', 'consistency on compilation: type of returned value is correct')
+
+os.exit(test:check() and 0 or 1)