diff --git a/mbtrack2/utilities/misc.py b/mbtrack2/utilities/misc.py
index a5d45013a3be194eb8ce6ae3fd25b47600a3c692..e58a848e9aed95336ced13ff1efbb71bded8319f 100644
--- a/mbtrack2/utilities/misc.py
+++ b/mbtrack2/utilities/misc.py
@@ -221,8 +221,8 @@ def yokoya_elliptic(x_radius, y_radius):
             small_semiaxis = x_radius
             large_semiaxis = y_radius
 
-        # Our equations are approximately valid only for qr (ratio) values less than or equal to 0.9.
-        qr_th = 0.9
+        # Our equations are approximately valid only for qr (ratio) values less than or equal to 0.8.
+        qr_th = 0.8
         F = np.sqrt(large_semiaxis**2 - small_semiaxis**2)
         mu_b = np.arccosh(large_semiaxis/F)
         qr = (large_semiaxis - small_semiaxis) / (large_semiaxis + small_semiaxis)