diff --git a/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp b/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
index cffcf1a7b5..0a7dc29003 100644
--- a/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
+++ b/Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
@@ -113,8 +113,11 @@ Optional<Bytecode::Register> BinaryExpression::generate_bytecode(Bytecode::Gener
     case BinaryOp::In:
         generator.emit<Bytecode::Op::In>(dst_reg, *lhs_reg, *rhs_reg);
         return dst_reg;
+    case BinaryOp::InstanceOf:
+        generator.emit<Bytecode::Op::InstanceOf>(dst_reg, *lhs_reg, *rhs_reg);
+        return dst_reg;
     default:
-        TODO();
+        VERIFY_NOT_REACHED();
     }
 }
 
diff --git a/Userland/Libraries/LibJS/Bytecode/Instruction.h b/Userland/Libraries/LibJS/Bytecode/Instruction.h
index bb52b84cc9..11d0bf2978 100644
--- a/Userland/Libraries/LibJS/Bytecode/Instruction.h
+++ b/Userland/Libraries/LibJS/Bytecode/Instruction.h
@@ -49,7 +49,8 @@
     O(LeftShift)                  \
     O(RightShift)                 \
     O(UnsignedRightShift)         \
-    O(In)
+    O(In)                         \
+    O(InstanceOf)
 
 namespace JS::Bytecode {
 
diff --git a/Userland/Libraries/LibJS/Bytecode/Op.cpp b/Userland/Libraries/LibJS/Bytecode/Op.cpp
index f44086f3e9..1e8d6878bd 100644
--- a/Userland/Libraries/LibJS/Bytecode/Op.cpp
+++ b/Userland/Libraries/LibJS/Bytecode/Op.cpp
@@ -163,6 +163,11 @@ void In::execute(Bytecode::Interpreter& interpreter) const
     interpreter.reg(m_dst) = in(interpreter.global_object(), interpreter.reg(m_src1), interpreter.reg(m_src2));
 }
 
+void InstanceOf::execute(Bytecode::Interpreter& interpreter) const
+{
+    interpreter.reg(m_dst) = instance_of(interpreter.global_object(), interpreter.reg(m_src1), interpreter.reg(m_src2));
+}
+
 void BitwiseNot::execute(Bytecode::Interpreter& interpreter) const
 {
     interpreter.reg(m_dst) = bitwise_not(interpreter.global_object(), interpreter.reg(m_src));
@@ -405,6 +410,11 @@ String In::to_string() const
     return String::formatted("In dst:{}, src1:{}, src2:{}", m_dst, m_src1, m_src2);
 }
 
+String InstanceOf::to_string() const
+{
+    return String::formatted("In dst:{}, src1:{}, src2:{}", m_dst, m_src1, m_src2);
+}
+
 String BitwiseNot::to_string() const
 {
     return String::formatted("BitwiseNot dst:{}, src:{}", m_dst, m_src);
diff --git a/Userland/Libraries/LibJS/Bytecode/Op.h b/Userland/Libraries/LibJS/Bytecode/Op.h
index 998e344d0e..7dd8cb945c 100644
--- a/Userland/Libraries/LibJS/Bytecode/Op.h
+++ b/Userland/Libraries/LibJS/Bytecode/Op.h
@@ -449,6 +449,25 @@ private:
     Register m_src2;
 };
 
+class InstanceOf final : public Instruction {
+public:
+    InstanceOf(Register dst, Register src1, Register src2)
+        : Instruction(Type::InstanceOf)
+        , m_dst(dst)
+        , m_src1(src1)
+        , m_src2(src2)
+    {
+    }
+
+    void execute(Bytecode::Interpreter&) const;
+    String to_string() const;
+
+private:
+    Register m_dst;
+    Register m_src1;
+    Register m_src2;
+};
+
 class BitwiseNot final : public Instruction {
 public:
     BitwiseNot(Register dst, Register src)