diff --git a/include/sirit/sirit.h b/include/sirit/sirit.h
index 2fa1d24..21cde3d 100644
--- a/include/sirit/sirit.h
+++ b/include/sirit/sirit.h
@@ -233,13 +233,13 @@ class Module {
     Id OpUndef(Id result_type);
 
   private:
-    Id AddCode(Op* op);
+    Id AddCode(std::unique_ptr<Op> op);
 
     Id AddCode(spv::Op opcode, std::optional<std::uint32_t> id = {});
 
-    Id AddDeclaration(Op* op);
+    Id AddDeclaration(std::unique_ptr<Op> op);
 
-    Id AddAnnotation(Op* op);
+    Id AddAnnotation(std::unique_ptr<Op> op);
 
     std::uint32_t bound{1};
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 86e33d3..3f3ff24 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -12,7 +12,6 @@ add_library(sirit
     literal_string.cpp
     literal_string.h
     common_types.h
-    insts.h
     insts/type.cpp
     insts/constant.cpp
     insts/function.cpp
diff --git a/src/insts.h b/src/insts.h
deleted file mode 100644
index b08b58a..0000000
--- a/src/insts.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/* This file is part of the sirit project.
- * Copyright (c) 2018 ReinUsesLisp
- * This software may be used and distributed according to the terms of the GNU
- * Lesser General Public License version 2.1 or any later version.
- */
-
-#pragma once
-
-#include "op.h"
-#include "stream.h"
-
-namespace Sirit {
-
-template <typename T> inline void AddEnum(Op* op, T value) {
-    op->Add(static_cast<u32>(value));
-}
-
-} // namespace Sirit
diff --git a/src/insts/annotation.cpp b/src/insts/annotation.cpp
index 7fe9d37..400af8d 100644
--- a/src/insts/annotation.cpp
+++ b/src/insts/annotation.cpp
@@ -4,29 +4,32 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include "insts.h"
+#include "common_types.h"
+#include "op.h"
 #include "sirit/sirit.h"
+#include <memory>
+#include <vector>
 
 namespace Sirit {
 
 Id Module::Decorate(Id target, spv::Decoration decoration,
-                     const std::vector<Literal>& literals) {
-    auto op{new Op(spv::Op::OpDecorate)};
+                    const std::vector<Literal>& literals) {
+    auto op{std::make_unique<Op>(spv::Op::OpDecorate)};
     op->Add(target);
-    AddEnum(op, decoration);
+    op->Add(static_cast<u32>(decoration));
     op->Add(literals);
-    return AddAnnotation(op);
+    return AddAnnotation(std::move(op));
 }
 
 Id Module::MemberDecorate(Id structure_type, Literal member,
-                           spv::Decoration decoration,
-                           const std::vector<Literal>& literals) {
-    auto op{new Op(spv::Op::OpMemberDecorate)};
+                          spv::Decoration decoration,
+                          const std::vector<Literal>& literals) {
+    auto op{std::make_unique<Op>(spv::Op::OpMemberDecorate)};
     op->Add(structure_type);
     op->Add(member);
-    AddEnum(op, decoration);
+    op->Add(static_cast<u32>(decoration));
     op->Add(literals);
-    return AddAnnotation(op);
+    return AddAnnotation(std::move(op));
 }
 
 } // namespace Sirit
diff --git a/src/insts/constant.cpp b/src/insts/constant.cpp
index ec0c730..507b3f4 100644
--- a/src/insts/constant.cpp
+++ b/src/insts/constant.cpp
@@ -4,48 +4,53 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include "insts.h"
+#include "op.h"
 #include "sirit/sirit.h"
 #include <cassert>
 
 namespace Sirit {
 
 Id Module::OpConstantTrue(Id result_type) {
-    return AddDeclaration(new Op(spv::Op::OpConstantTrue, bound, result_type));
+    return AddDeclaration(
+        std::make_unique<Op>(spv::Op::OpConstantTrue, bound, result_type));
 }
 
 Id Module::OpConstantFalse(Id result_type) {
-    return AddDeclaration(new Op(spv::Op::OpConstantFalse, bound, result_type));
+    return AddDeclaration(
+        std::make_unique<Op>(spv::Op::OpConstantFalse, bound, result_type));
 }
 
 Id Module::OpConstant(Id result_type, const Literal& literal) {
-    auto op{new Op(spv::Op::OpConstant, bound, result_type)};
+    auto op{std::make_unique<Op>(spv::Op::OpConstant, bound, result_type)};
     op->Add(literal);
-    return AddDeclaration(op);
+    return AddDeclaration(std::move(op));
 }
 
 Id Module::OpConstantComposite(Id result_type,
-                                const std::vector<Id>& constituents) {
-    auto op{new Op(spv::Op::OpConstantComposite, bound, result_type)};
+                               const std::vector<Id>& constituents) {
+    auto op{
+        std::make_unique<Op>(spv::Op::OpConstantComposite, bound, result_type)};
     op->Add(constituents);
-    return AddDeclaration(op);
+    return AddDeclaration(std::move(op));
 }
 
 Id Module::OpConstantSampler(Id result_type,
-                              spv::SamplerAddressingMode addressing_mode,
-                              bool normalized,
-                              spv::SamplerFilterMode filter_mode) {
+                             spv::SamplerAddressingMode addressing_mode,
+                             bool normalized,
+                             spv::SamplerFilterMode filter_mode) {
     AddCapability(spv::Capability::LiteralSampler);
     AddCapability(spv::Capability::Kernel);
-    auto op{new Op(spv::Op::OpConstantSampler, bound, result_type)};
-    AddEnum(op, addressing_mode);
+    auto op{
+        std::make_unique<Op>(spv::Op::OpConstantSampler, bound, result_type)};
+    op->Add(static_cast<u32>(addressing_mode));
     op->Add(normalized ? 1 : 0);
-    AddEnum(op, filter_mode);
-    return AddDeclaration(op);
+    op->Add(static_cast<u32>(filter_mode));
+    return AddDeclaration(std::move(op));
 }
 
 Id Module::OpConstantNull(Id result_type) {
-    return AddDeclaration(new Op(spv::Op::OpConstantNull, bound, result_type));
+    return AddDeclaration(
+        std::make_unique<Op>(spv::Op::OpConstantNull, bound, result_type));
 }
 
 } // namespace Sirit
diff --git a/src/insts/debug.cpp b/src/insts/debug.cpp
index 04b544a..072833b 100644
--- a/src/insts/debug.cpp
+++ b/src/insts/debug.cpp
@@ -4,16 +4,18 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include "insts.h"
+#include "op.h"
 #include "sirit/sirit.h"
+#include <memory>
+#include <string>
 
 namespace Sirit {
 
 Id Module::Name(Id target, const std::string& name) {
-    auto op{new Op(spv::Op::OpName)};
+    auto op{std::make_unique<Op>(spv::Op::OpName)};
     op->Add(target);
     op->Add(name);
-    debug.push_back(std::unique_ptr<Op>(op));
+    debug.push_back(std::move(op));
     return target;
 }
 
diff --git a/src/insts/flow.cpp b/src/insts/flow.cpp
index f956d0c..afd0244 100644
--- a/src/insts/flow.cpp
+++ b/src/insts/flow.cpp
@@ -4,42 +4,43 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include "insts.h"
+#include "common_types.h"
+#include "op.h"
 #include "sirit/sirit.h"
+#include <vector>
 
 namespace Sirit {
 
 Id Module::OpLoopMerge(Id merge_block, Id continue_target,
-                        spv::LoopControlMask loop_control,
-                        const std::vector<Id>& literals) {
-    auto op{new Op(spv::Op::OpLoopMerge)};
+                       spv::LoopControlMask loop_control,
+                       const std::vector<Id>& literals) {
+    auto op{std::make_unique<Op>(spv::Op::OpLoopMerge)};
     op->Add(merge_block);
     op->Add(continue_target);
-    AddEnum(op, loop_control);
+    op->Add(static_cast<u32>(loop_control));
     op->Add(literals);
-    return AddCode(op);
+    return AddCode(std::move(op));
 }
 
 Id Module::OpSelectionMerge(Id merge_block,
-                             spv::SelectionControlMask selection_control) {
-    auto op{new Op(spv::Op::OpSelectionMerge)};
+                            spv::SelectionControlMask selection_control) {
+    auto op{std::make_unique<Op>(spv::Op::OpSelectionMerge)};
     op->Add(merge_block);
-    AddEnum(op, selection_control);
-    return AddCode(op);
+    op->Add(static_cast<u32>(selection_control));
+    return AddCode(std::move(op));
 }
 
 Id Module::OpLabel() { return AddCode(spv::Op::OpLabel, bound++); }
 
 Id Module::OpBranch(Id target_label) {
-    auto op{new Op(spv::Op::OpBranch)};
+    auto op{std::make_unique<Op>(spv::Op::OpBranch)};
     op->Add(target_label);
-    return AddCode(op);
+    return AddCode(std::move(op));
 }
 
 Id Module::OpBranchConditional(Id condition, Id true_label, Id false_label,
-                                std::uint32_t true_weight,
-                                std::uint32_t false_weight) {
-    auto op{new Op(spv::Op::OpBranchConditional)};
+                               u32 true_weight, u32 false_weight) {
+    auto op{std::make_unique<Op>(spv::Op::OpBranchConditional)};
     op->Add(condition);
     op->Add(true_label);
     op->Add(false_label);
@@ -47,7 +48,7 @@ Id Module::OpBranchConditional(Id condition, Id true_label, Id false_label,
         op->Add(true_weight);
         op->Add(false_weight);
     }
-    return AddCode(op);
+    return AddCode(std::move(op));
 }
 
 Id Module::OpReturn() { return AddCode(spv::Op::OpReturn); }
diff --git a/src/insts/function.cpp b/src/insts/function.cpp
index f686d64..dcd803a 100644
--- a/src/insts/function.cpp
+++ b/src/insts/function.cpp
@@ -4,18 +4,18 @@
  * Lesser General Public License version 2.1 or any later version.
  */
 
-#include "insts.h"
+#include "common_types.h"
+#include "op.h"
 #include "sirit/sirit.h"
 
 namespace Sirit {
 
-Id Module::OpFunction(Id result_type,
-                       spv::FunctionControlMask function_control,
-                       Id function_type) {
-    auto op{new Op{spv::Op::OpFunction, bound++, result_type}};
+Id Module::OpFunction(Id result_type, spv::FunctionControlMask function_control,
+                      Id function_type) {
+    auto op{std::make_unique<Op>(spv::Op::OpFunction, bound++, result_type)};
     op->Add(static_cast<u32>(function_control));
     op->Add(function_type);
-    return AddCode(op);
+    return AddCode(std::move(op));
 }
 
 Id Module::OpFunctionEnd() { return AddCode(spv::Op::OpFunctionEnd); }
diff --git a/src/sirit.cpp b/src/sirit.cpp
index bb92a13..d4b7fdd 100644
--- a/src/sirit.cpp
+++ b/src/sirit.cpp
@@ -84,7 +84,6 @@ void Module::AddEntryPoint(spv::ExecutionModel execution_model, Id entry_point,
 }
 
 Id Module::Emit(Id op) {
-    assert(op);
     code.push_back(op);
     return op;
 }
@@ -95,34 +94,31 @@ Id Module::AddGlobalVariable(Id variable) {
     return variable;
 }
 
-Id Module::AddCode(Op* op) {
-    assert(op);
-    code_store.push_back(std::unique_ptr<Op>(op));
-    return op;
+Id Module::AddCode(std::unique_ptr<Op> op) {
+    code_store.push_back(std::move(op));
+    return op.get();
 }
 
 Id Module::AddCode(spv::Op opcode, std::optional<u32> id) {
-    return AddCode(new Op(opcode, id));
+    return AddCode(std::make_unique<Op>(opcode, id));
 }
 
-Id Module::AddDeclaration(Op* op) {
+Id Module::AddDeclaration(std::unique_ptr<Op> op) {
     const auto& found{
         std::find_if(declarations.begin(), declarations.end(),
                      [&op](const auto& other) { return *other == *op; })};
     if (found != declarations.end()) {
-        delete op;
         return found->get();
-    } else {
-        declarations.push_back(std::unique_ptr<Op>(op));
-        bound++;
-        return op;
     }
+    const auto id = op.get();
+    declarations.push_back(std::move(op));
+    bound++;
+    return id;
 }
 
-Id Module::AddAnnotation(Op* op) {
-    assert(op);
-    annotations.push_back(std::unique_ptr<Op>(op));
-    return op;
+Id Module::AddAnnotation(std::unique_ptr<Op> op) {
+    annotations.push_back(std::move(op));
+    return op.get();
 }
 
 } // namespace Sirit