diff --git a/day02.cpp b/day02.cpp
index ee0effc..2358984 100644
--- a/day02.cpp
+++ b/day02.cpp
@@ -1,7 +1,7 @@
 #include <iostream>
 #include <utility>
 
-#include <intcode.hpp>
+#include <intcode/intcode.hpp>
 
 using namespace intcode;
 
diff --git a/day05.cpp b/day05.cpp
index 4e3b4af..92f1dc4 100644
--- a/day05.cpp
+++ b/day05.cpp
@@ -1,7 +1,7 @@
 #include <iostream>
 #include <utility>
 
-#include <intcode.hpp>
+#include <intcode/intcode.hpp>
 using namespace intcode;
 
 namespace {
diff --git a/day07.cpp b/day07.cpp
index 06162a3..06d1c0e 100644
--- a/day07.cpp
+++ b/day07.cpp
@@ -5,7 +5,7 @@
 #include <utility>
 #include <vector>
 
-#include <intcode.hpp>
+#include <intcode/intcode.hpp>
 using namespace intcode;
 
 namespace {
diff --git a/day09.cpp b/day09.cpp
index 8570af3..0779504 100644
--- a/day09.cpp
+++ b/day09.cpp
@@ -1,7 +1,7 @@
 #include <iostream>
 #include <utility>
 
-#include <intcode.hpp>
+#include <intcode/intcode.hpp>
 using namespace intcode;
 
 namespace {
diff --git a/day11.cpp b/day11.cpp
index 137f6dd..7f98690 100644
--- a/day11.cpp
+++ b/day11.cpp
@@ -3,7 +3,7 @@
 #include <tuple>
 #include <map>
 
-#include <intcode.hpp>
+#include <intcode/intcode.hpp>
 using namespace intcode;
 
 namespace {
diff --git a/day13.cpp b/day13.cpp
index a16201a..52db32d 100644
--- a/day13.cpp
+++ b/day13.cpp
@@ -3,7 +3,7 @@
 #include <tuple>
 #include <set>
 
-#include <intcode.hpp>
+#include <intcode/intcode.hpp>
 using namespace intcode;
 
 namespace {
diff --git a/day15.cpp b/day15.cpp
index a351318..d6bcdb1 100644
--- a/day15.cpp
+++ b/day15.cpp
@@ -6,7 +6,7 @@
 #include <deque>
 #include <vector>
 
-#include <intcode.hpp>
+#include <intcode/intcode.hpp>
 using namespace intcode;
 
 namespace {
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 047637c..e10e3fc 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -1,2 +1,2 @@
-add_library(intcode intcode.cpp)
-target_include_directories(intcode PUBLIC include)
\ No newline at end of file
+add_library(intcode src/Parser.cpp src/Interpreter.cpp src/Machine.cpp)
+target_include_directories(intcode PUBLIC include)
diff --git a/lib/include/intcode/Interpreter.hpp b/lib/include/intcode/Interpreter.hpp
new file mode 100644
index 0000000..bb8967a
--- /dev/null
+++ b/lib/include/intcode/Interpreter.hpp
@@ -0,0 +1,26 @@
+#ifndef INTCODE_INTERPRETER_HPP_
+#define INTCODE_INTERPRETER_HPP_
+
+#include "Machine.hpp"
+
+namespace intcode {
+
+struct Input {
+ValueType &pos;
+};
+
+struct Output {
+ValueType val;
+};
+
+struct Halt {};
+
+auto Step(Machine & m) -> std::variant<Input, Output, Halt>;
+
+struct BadInstruction : public std::runtime_error {
+  explicit BadInstruction(char const* what);
+};
+
+} // namespace
+
+#endif
diff --git a/lib/include/intcode.hpp b/lib/include/intcode/Machine.hpp
similarity index 54%
rename from lib/include/intcode.hpp
rename to lib/include/intcode/Machine.hpp
index a78dd7f..2066f98 100644
--- a/lib/include/intcode.hpp
+++ b/lib/include/intcode/Machine.hpp
@@ -1,30 +1,13 @@
-#ifndef INTCODE_HPP_
-#define INTCODE_HPP_
+#ifndef INTCODE_MACHINE_HPP_
+#define INTCODE_MACHINE_HPP_
 
 #include <cstddef>
-#include <cstdint>
-#include <istream>
 #include <unordered_map>
-#include <stdexcept>
-#include <variant>
 #include <vector>
 
-template <class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
-template <class... Ts> overloaded(Ts...) -> overloaded<Ts...>;
-
 namespace intcode {
 
-  using ValueType = std::int64_t;
-
-  struct Input {
-    ValueType &pos;
-  };
-
-  struct Output {
-    ValueType val;
-  };
-
-  struct Halt {};
+using ValueType = std::int64_t;
 
 class Machine {
   std::vector<ValueType> rom_;
@@ -51,14 +34,6 @@ public:
   auto Rebase(std::size_t offset) -> void;
 };
 
-auto Step(Machine & m) -> std::variant<Input, Output, Halt>;
+} // namespace
 
-struct BadInstruction : public std::runtime_error {
-  explicit BadInstruction(char const* what);
-};
-
-auto ParseStream(std::istream &in) -> std::vector<ValueType>;
-
-}
-
-#endif // INTCODE_HPP_
+#endif
diff --git a/lib/include/intcode/Parser.hpp b/lib/include/intcode/Parser.hpp
new file mode 100644
index 0000000..e696863
--- /dev/null
+++ b/lib/include/intcode/Parser.hpp
@@ -0,0 +1,15 @@
+#ifndef INTCODE_PARSER_HPP_
+#define INTCODE_PARSER_HPP_
+
+#include <istream>
+#include <vector>
+
+#include "Machine.hpp"
+
+namespace intcode {
+
+auto ParseStream(std::istream &in) -> std::vector<ValueType>;
+
+} // namespace
+
+#endif
diff --git a/lib/include/intcode/intcode.hpp b/lib/include/intcode/intcode.hpp
new file mode 100644
index 0000000..a56803b
--- /dev/null
+++ b/lib/include/intcode/intcode.hpp
@@ -0,0 +1,11 @@
+#ifndef INTCODE_HPP_
+#define INTCODE_INTCODE_HPP_
+
+#include <intcode/Machine.hpp>
+#include <intcode/Parser.hpp>
+#include <intcode/Interpreter.hpp>
+
+template <class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
+template <class... Ts> overloaded(Ts...) -> overloaded<Ts...>;
+
+#endif
diff --git a/lib/intcode.cpp b/lib/src/Interpreter.cpp
similarity index 65%
rename from lib/intcode.cpp
rename to lib/src/Interpreter.cpp
index 00e1c2b..59df270 100644
--- a/lib/intcode.cpp
+++ b/lib/src/Interpreter.cpp
@@ -1,37 +1,10 @@
-#include "intcode.hpp"
-#include <iostream>
+#include <intcode/Interpreter.hpp>
 
 namespace intcode {
 
 BadInstruction::BadInstruction(char const* what)
     : std::runtime_error{what} {}
 
-Machine::Machine() : rom_{}, ram_{}, pc_{0}, base_{0} {}
-
-Machine::Machine(std::vector<ValueType> ram)
-    : rom_{ram}, ram_{}, pc_{0}, base_{0} {}
-
-auto Machine::At(std::size_t i) -> ValueType & {
-  return i < rom_.size() ? rom_[i] : ram_[i];
-}
-
-auto Machine::Rel(std::size_t i) -> ValueType & {
-  return At(base_ + i);
-}
-
-auto Machine::Rebase(std::size_t offset) -> void {
-  base_ += offset;
-}
-
-
-auto Machine::Next() -> ValueType & {
-  return At(pc_++);
-}
-
-auto Machine::Goto(std::size_t address) -> void {
-  pc_ = address;
-}
-
 auto Step(Machine & m) -> std::variant<Input, Output, Halt> {
   for (;;) {
     auto instruction = m.Next();
@@ -119,14 +92,4 @@ auto Step(Machine & m) -> std::variant<Input, Output, Halt> {
   }
 }
 
-auto ParseStream(std::istream &in) -> std::vector<ValueType> {
-  ValueType x;
-  std::string str;
-  std::vector<ValueType> result;
-  while (std::getline(in, str, ',')) {
-    result.push_back(std::stol(str));
-  }
-  return result;
-}
-
-}
+} // namespace
diff --git a/lib/src/Machine.cpp b/lib/src/Machine.cpp
new file mode 100644
index 0000000..e7737cf
--- /dev/null
+++ b/lib/src/Machine.cpp
@@ -0,0 +1,30 @@
+#include <intcode/Machine.hpp>
+
+namespace intcode {
+
+Machine::Machine() : rom_{}, ram_{}, pc_{0}, base_{0} {}
+
+Machine::Machine(std::vector<ValueType> ram)
+    : rom_{ram}, ram_{}, pc_{0}, base_{0} {}
+
+auto Machine::At(std::size_t i) -> ValueType & {
+  return i < rom_.size() ? rom_[i] : ram_[i];
+}
+
+auto Machine::Rel(std::size_t i) -> ValueType & {
+  return At(base_ + i);
+}
+
+auto Machine::Rebase(std::size_t offset) -> void {
+  base_ += offset;
+}
+
+auto Machine::Next() -> ValueType & {
+  return At(pc_++);
+}
+
+auto Machine::Goto(std::size_t address) -> void {
+  pc_ = address;
+}
+
+} // namespace
diff --git a/lib/src/Parser.cpp b/lib/src/Parser.cpp
new file mode 100644
index 0000000..cf489e7
--- /dev/null
+++ b/lib/src/Parser.cpp
@@ -0,0 +1,17 @@
+#include <intcode/Parser.hpp>
+
+#include <iostream>
+
+namespace intcode {
+
+auto ParseStream(std::istream &in) -> std::vector<ValueType> {
+  ValueType x;
+  std::string str;
+  std::vector<ValueType> result;
+  while (std::getline(in, str, ',')) {
+    result.push_back(std::stol(str));
+  }
+  return result;
+}
+
+} // namespace