diff --git a/src/util/format/builder.cpp b/src/util/format/builder.cpp
index 85ddc62..bed899a 100644
--- a/src/util/format/builder.cpp
+++ b/src/util/format/builder.cpp
@@ -28,6 +28,64 @@ void Builder::putLiteral(std::string_view literal)
 	}
 }
 
+void Builder::putU64(size_t value, size_t width, Align align, char fill, Sign sign, bool isNegative) const
+{
+	std::string string = (std::stringstream {} << value).str();
+
+	printf("sign {%c}\n", (char)sign);
+	// Sign
+	switch (sign) {
+	case Sign::None:
+	case Sign::Negative:
+		if (isNegative) {
+			string.insert(0, 1, '-');
+		}
+		break;
+	case Sign::Both:
+		string.insert(0, 1, (isNegative) ? '-' : '+');
+		break;
+	case Sign::Space:
+		string.insert(0, 1, (isNegative) ? '-' : ' ');
+		break;
+	default:
+		VERIFY_NOT_REACHED();
+	};
+
+	size_t length = string.length();
+	if (width < length) {
+		m_builder.write(string.data(), length);
+		return;
+	}
+
+	switch (align) {
+	case Align::Left:
+		m_builder.write(string.data(), length);
+		m_builder << std::string(width - length, fill);
+		break;
+	case Align::Center: {
+		size_t half = (width - length) / 2;
+		m_builder << std::string(half, fill);
+		m_builder.write(string.data(), length);
+		m_builder << std::string(width - half - length, fill);
+		break;
+	}
+	case Align::None:
+	case Align::Right:
+		m_builder << std::string(width - length, fill);
+		m_builder.write(string.data(), length);
+		break;
+	default:
+		VERIFY_NOT_REACHED();
+	};
+}
+
+void Builder::putI64(int64_t value, size_t width, Align align, char fill, Sign sign) const
+{
+	auto const isNegative = value < 0;
+    value = isNegative ? -value : value;
+    putU64(static_cast<uint64_t>(value), width, align, fill, sign, isNegative);
+}
+
 void Builder::putF64(double number, uint8_t precision) const
 {
 	precision = std::min(precision, static_cast<uint8_t>(std::numeric_limits<double>::digits10));
diff --git a/src/util/format/builder.h b/src/util/format/builder.h
index aaeded3..a6848ce 100644
--- a/src/util/format/builder.h
+++ b/src/util/format/builder.h
@@ -36,8 +36,8 @@ public:
 
 	void putLiteral(std::string_view literal);
 
-	void putI64(int64_t number) const { m_builder << number; } // long int
-	void putU64(size_t number) const { m_builder << number; }  // long unsigned int
+	void putU64(size_t value, size_t width = 0, Align align = Align::Right, char fill = ' ', Sign sign = Sign::Negative, bool isNegative = false) const;
+	void putI64(int64_t value, size_t width = 0, Align align = Align::Right, char fill = ' ', Sign sign = Sign::Negative) const;
 	void putF64(double number, uint8_t precision = 6) const;
 	void putCharacter(char character) const { m_builder.write(&character, 1); }
 	void putString(std::string_view string, size_t width = 0, Align align = Align::Left, char fill = ' ') const;
diff --git a/src/util/format/formatter.h b/src/util/format/formatter.h
index 8c602c3..def836c 100644
--- a/src/util/format/formatter.h
+++ b/src/util/format/formatter.h
@@ -92,10 +92,12 @@ struct Formatter<T> {
 	void format(Builder& builder, T value) const
 	{
 		if (std::is_signed_v<T>) {
-			builder.putI64(value);
+			builder.putI64(
+				value, specifier.width, specifier.align, specifier.fill, specifier.sign);
 		}
 		if (std::is_unsigned_v<T>) {
-			builder.putU64(value);
+			builder.putU64(
+				value, specifier.width, specifier.align, specifier.fill, specifier.sign);
 		}
 	}
 };