diff --git a/src/Shape.jl b/src/Shape.jl
index 9975b5c..7b7419b 100644
--- a/src/Shape.jl
+++ b/src/Shape.jl
@@ -6,7 +6,7 @@ export center_of_mass,
 using StaticArrays: SVector, SMatrix
 using LinearAlgebra: eigvals, eigvecs, Hermitian, dot
 
-using ..ReCo: Particle
+using ..ReCo: ReCo, Particle
 
 function project_to_unit_circle(x::Float64, half_box_len::Float64)
     φ = (x + half_box_len) * π / half_box_len
@@ -126,7 +126,7 @@ function elliptical_distance(
     x = dot(v′, gyration_tensor_eigvec_to_bigger_eigval)
     y = dot(v′, gyration_tensor_eigvec_to_smaller_eigval)
 
-    return x^2 + (y / goal_gyration_tensor_eigvals_ratio)^2
+    return sqrt(x^2 + (y / goal_gyration_tensor_eigvals_ratio)^2)
 end
 
 end # module
\ No newline at end of file