diff --git a/rtchallenge/src/matrices.rs b/rtchallenge/src/matrices.rs
index 6363d13..1fda39d 100644
--- a/rtchallenge/src/matrices.rs
+++ b/rtchallenge/src/matrices.rs
@@ -481,7 +481,7 @@ impl Matrix4x4 {
     /// use rtchallenge::matrices::Matrix4x4;
     ///
     /// let i = Matrix4x4::identity();
-    /// assert_eq!(i.inverse_old() * i, i);
+    /// assert_eq!(i.inverse_rtiow() * i, i);
     ///
     /// let m = Matrix4x4::new(
     ///     [2., 0., 0., 0.],
@@ -489,10 +489,10 @@ impl Matrix4x4 {
     ///     [0., 0., 4., 0.],
     ///     [0., 0., 0., 1.],
     /// );
-    /// assert_eq!(m.inverse_old() * m, i);
-    /// assert_eq!(m * m.inverse_old(), i);
+    /// assert_eq!(m.inverse_rtiow() * m, i);
+    /// assert_eq!(m * m.inverse_rtiow(), i);
     /// ```
-    pub fn inverse_old(&self) -> Matrix4x4 {
+    pub fn inverse_rtiow(&self) -> Matrix4x4 {
         // TODO(wathiede): how come the C++ version doesn't need to deal with non-invertable
         // matrix.
         let mut indxc: [usize; 4] = Default::default();
@@ -743,6 +743,9 @@ impl Matrix4x4 {
     /// assert_eq!(c * b.inverse(), a);
     /// ```
     pub fn inverse(&self) -> Matrix4x4 {
+        self.inverse_rtc()
+    }
+    pub fn inverse_rtc(&self) -> Matrix4x4 {
         let m = self;
         if !m.invertable() {
             panic!("Matrix4x4::inverse called on matrix with determinant() == 0");