diff --git a/src/trust-region/ar-trust-region.jl b/src/trust-region/ar-trust-region.jl
index 6c1d887..a3d165c 100644
--- a/src/trust-region/ar-trust-region.jl
+++ b/src/trust-region/ar-trust-region.jl
@@ -1,4 +1,4 @@
-export ARTrustRegion
+export ARTrustRegion, compute_r
 
 """
 ARTrustRegion(α₀::T;kwargs...)