diff --git a/SimPkg_F21(student_ver)/xenia_nonlinearopt.m b/SimPkg_F21(student_ver)/xenia_nonlinearopt.m
index 92e6b59..3ba188c 100644
--- a/SimPkg_F21(student_ver)/xenia_nonlinearopt.m
+++ b/SimPkg_F21(student_ver)/xenia_nonlinearopt.m
@@ -52,7 +52,7 @@ function [lb, ub] = bounds(StepsPerPoint)
     phi_init = TestTrack.theta(1);
     
     %phi restricted to just [-pi/2 pi/2]
-    lb = [min(bound_X); -Inf; min(bound_Y); -Inf; -pi); -Inf];
+    lb = [min(bound_X); -Inf; min(bound_Y); -Inf; -pi; -Inf];
     ub = [max(bound_X); Inf; max(bound_Y); Inf; +pi; Inf];