diff --git a/Angle.h b/Angle.h
index 6b15e6f..328354b 100644
--- a/Angle.h
+++ b/Angle.h
@@ -36,6 +36,13 @@ class AngleOf {
   AngleOf<T> operator-(const AngleOf<T>& a) const;
   AngleOf<T> operator+(const AngleOf<T>& a) const;
 
+  friend AngleOf<T> operator*(const AngleOf<T>& a, float f) {
+    return AngleOf((float)a.ToFloat() * f);
+  }
+  friend AngleOf<T> operator*(float f, const AngleOf<T>& a) {
+    return AngleOf((float)f * a.ToFloat());
+  }
+
   static AngleOf<T> Normalize(AngleOf<T> a);
   static AngleOf<T> Clamp(AngleOf<T> a, AngleOf<T> min, AngleOf<T> max);
   static AngleOf<T> Difference(AngleOf<T> a, AngleOf<T> b) {