diff --git a/include/mtl/fixed.hpp b/include/mtl/fixed.hpp
index ab536de..090daa2 100644
--- a/include/mtl/fixed.hpp
+++ b/include/mtl/fixed.hpp
@@ -117,6 +117,9 @@ public:
 	constexpr fixed operator-(fixed rhs) const {
 		return from_raw(x - rhs.x);
 	}
+	constexpr fixed operator-() const {
+		return from_raw(-x);
+	}
 
 	/**
 	 * \brief Fixed point multiplication