diff --git a/inc/InputOutput.h b/inc/InputOutput.h
index a4ffb0f..e3d6d78 100644
--- a/inc/InputOutput.h
+++ b/inc/InputOutput.h
@@ -10,7 +10,7 @@ namespace EightBit {
 	public:
 		enum class AccessType { Unknown, Reading, Writing };
 
-		[[nodiscard]] size_t size() const noexcept override;
+		[[nodiscard]] uint16_t size() const noexcept override;
 		[[nodiscard]] uint8_t peek(uint16_t address) const noexcept override;
 
 		[[nodiscard]] uint8_t& reference(uint16_t address) noexcept override;
diff --git a/inc/Memory.h b/inc/Memory.h
index baaa5cb..e8076f3 100644
--- a/inc/Memory.h
+++ b/inc/Memory.h
@@ -16,7 +16,7 @@ namespace EightBit {
 	public:
 		virtual ~Memory() {};
 
-		[[nodiscard]] virtual size_t size() const noexcept = 0;
+		[[nodiscard]] virtual uint16_t size() const noexcept = 0;
 		[[nodiscard]] virtual uint8_t peek(uint16_t address) const noexcept = 0;
 
 		[[nodiscard]] virtual uint8_t& reference(uint16_t) noexcept;
diff --git a/inc/Rom.h b/inc/Rom.h
index ff47e2b..c988863 100644
--- a/inc/Rom.h
+++ b/inc/Rom.h
@@ -30,7 +30,7 @@ namespace EightBit {
 		Rom& operator=(const Rom& rhs);
 		bool operator==(const Rom& rhs) const;
 
-		[[nodiscard]] size_t size() const noexcept final;
+		[[nodiscard]] uint16_t size() const noexcept final;
 
 		int load(std::ifstream& file, int writeOffset = 0, int readOffset = 0, int limit = -1) final;
 		int load(std::string path, int writeOffset = 0, int readOffset = 0, int limit = -1) final;
diff --git a/inc/UnusedMemory.h b/inc/UnusedMemory.h
index ec0e57a..cd60245 100644
--- a/inc/UnusedMemory.h
+++ b/inc/UnusedMemory.h
@@ -13,10 +13,10 @@ namespace EightBit {
 	// is being read.
 	class UnusedMemory final : public Memory {
 	public:
-		UnusedMemory(size_t size, uint8_t value) noexcept;
+		UnusedMemory(uint16_t size, uint8_t value) noexcept;
 		~UnusedMemory() = default;
 
-		[[nodiscard]] size_t size() const noexcept final;
+		[[nodiscard]] uint16_t size() const noexcept final;
 		[[nodiscard]] uint8_t peek(uint16_t address) const noexcept final;
 
 		int load(std::ifstream& file, int writeOffset = 0, int readOffset = 0, int limit = -1) final;
@@ -27,7 +27,7 @@ namespace EightBit {
 		void poke(uint16_t address, uint8_t value) noexcept final;
 
 	private:
-		size_t m_size;
+		uint16_t m_size;
 		uint8_t m_value;
 	};
 }
\ No newline at end of file
diff --git a/src/InputOutput.cpp b/src/InputOutput.cpp
index e4d2d49..34e611e 100644
--- a/src/InputOutput.cpp
+++ b/src/InputOutput.cpp
@@ -6,7 +6,7 @@
 
 #include "../inc/Register.h"
 
-size_t EightBit::InputOutput::size() const noexcept {
+uint16_t EightBit::InputOutput::size() const noexcept {
 	return 0x100;
 }
 
diff --git a/src/Rom.cpp b/src/Rom.cpp
index c8defd8..24cf331 100644
--- a/src/Rom.cpp
+++ b/src/Rom.cpp
@@ -57,8 +57,10 @@ EightBit::Rom& EightBit::Rom::operator=(const Rom& rhs) {
 	return *this;
 }
 
-size_t EightBit::Rom::size() const noexcept {
-	return m_bytes.size();
+uint16_t EightBit::Rom::size() const noexcept {
+	const auto size = BYTES().size();
+	assert(size <= 0x10000);
+	return static_cast<uint16_t>(size);
 }
 
 int EightBit::Rom::load(std::ifstream& file, const int writeOffset, const int readOffset, const int limit) {
diff --git a/src/UnusedMemory.cpp b/src/UnusedMemory.cpp
index f368930..405b8a7 100644
--- a/src/UnusedMemory.cpp
+++ b/src/UnusedMemory.cpp
@@ -3,10 +3,10 @@
 
 #include <cassert>
 
-EightBit::UnusedMemory::UnusedMemory(const size_t size, const uint8_t value) noexcept
+EightBit::UnusedMemory::UnusedMemory(const uint16_t size, const uint8_t value) noexcept
 : m_size(size), m_value(value) {}
 
-size_t EightBit::UnusedMemory::size() const noexcept {
+uint16_t EightBit::UnusedMemory::size() const noexcept {
 	return m_size;
 }