diff --git a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt
index 0c4161b..5fcc7d2 100644
--- a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt
+++ b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt
@@ -204,6 +204,29 @@ class BytecodeCompiler(
         if (op == BinOp.AND || op == BinOp.OR) {
             return compileLogical(op, binaryLeft(ref), binaryRight(ref), refPos(ref))
         }
+        if (op == BinOp.IN || op == BinOp.NOTIN) {
+            val leftValue = compileRefWithFallback(binaryLeft(ref), null, refPos(ref)) ?: return null
+            val rightValue = compileRefWithFallback(binaryRight(ref), null, refPos(ref)) ?: return null
+            val leftObj = ensureObjSlot(leftValue)
+            val rightObj = ensureObjSlot(rightValue)
+            val methodId = builder.addConst(BytecodeConst.StringVal("contains"))
+            if (methodId > 0xFFFF) return null
+            val argSlot = allocSlot()
+            builder.emit(Opcode.BOX_OBJ, leftObj.slot, argSlot)
+            updateSlotType(argSlot, SlotType.OBJ)
+            val callSlot = allocSlot()
+            builder.emit(Opcode.CALL_VIRTUAL, rightObj.slot, methodId, argSlot, 1, callSlot)
+            val boolSlot = allocSlot()
+            builder.emit(Opcode.OBJ_TO_BOOL, callSlot, boolSlot)
+            updateSlotType(boolSlot, SlotType.BOOL)
+            if (op == BinOp.NOTIN) {
+                val outSlot = allocSlot()
+                builder.emit(Opcode.NOT_BOOL, boolSlot, outSlot)
+                updateSlotType(outSlot, SlotType.BOOL)
+                return CompiledValue(outSlot, SlotType.BOOL)
+            }
+            return CompiledValue(boolSlot, SlotType.BOOL)
+        }
         val leftRef = binaryLeft(ref)
         val rightRef = binaryRight(ref)
         var a = compileRef(leftRef) ?: return null
diff --git a/lynglib/src/commonTest/kotlin/ScriptTest.kt b/lynglib/src/commonTest/kotlin/ScriptTest.kt
index 484a517..b8e3f3c 100644
--- a/lynglib/src/commonTest/kotlin/ScriptTest.kt
+++ b/lynglib/src/commonTest/kotlin/ScriptTest.kt
@@ -5201,6 +5201,20 @@ class ScriptTest {
         assertEquals(ObjInt(2), scope.eval("firstEvenOrMinus()"))
     }
 
+    @Test
+    fun testInOperatorBytecode() = runTest {
+        val scope = Script.newScope()
+        scope.eval(
+            """
+            fun inList(x, xs) { x in xs }
+            """.trimIndent()
+        )
+        val disasm = scope.disassembleSymbol("inList")
+        assertFalse(disasm.contains("not a compiled body"))
+        assertEquals(ObjTrue, scope.eval("inList(2, [1,2,3])"))
+        assertEquals(ObjFalse, scope.eval("inList(5, [1,2,3])"))
+    }
+
     @Test
     fun testFilterBug() = runTest {
         eval(