diff --git a/vector.cpp b/vector.cpp
index ee3903aa..0da22239 100644
--- a/vector.cpp
+++ b/vector.cpp
@@ -46,12 +46,34 @@ vector::operator*= (double rhs) {
 }
 
 
+util::vector
+util::vector::operator* (const vector &rhs) const {
+    return { x * rhs.x, y * rhs.y, z * rhs.z };
+}
+
+
+util::vector&
+util::vector::operator*= (const vector &rhs) {
+    x *= rhs.x;
+    y *= rhs.y;
+    z *= rhs.z;
+
+    return *this;
+}
+
+
 vector
 vector::operator+ (const vector &rhs) const {
     return { x + rhs.x, y + rhs.y, z + rhs.z };
 }
 
 
+vector
+vector::operator- (void) const {
+    return { -x, -y, -z };
+}
+
+
 vector
 vector::operator- (const vector &rhs) const
     { return { x - rhs.x, y - rhs.y, z - rhs.z }; }
diff --git a/vector.hpp b/vector.hpp
index 8cdd7bc3..6a56d0d2 100644
--- a/vector.hpp
+++ b/vector.hpp
@@ -28,10 +28,13 @@ namespace util {
 
         vector  operator* (double) const;
         vector& operator*=(double);
+        vector  operator* (const vector&) const;
+        vector& operator*=(const vector&);
 
         vector  operator+ (const vector&) const;
         vector& operator+=(const vector&);
 
+        vector  operator- (void) const;
         vector  operator- (const vector&) const;
         vector& operator-=(const vector&);