diff --git a/PathPlanning/QuinticPolynomialsPlanner/quintic_polynomials_planner.py b/PathPlanning/QuinticPolynomialsPlanner/quintic_polynomials_planner.py
index 86f9f662da..27a6ee61da 100644
--- a/PathPlanning/QuinticPolynomialsPlanner/quintic_polynomials_planner.py
+++ b/PathPlanning/QuinticPolynomialsPlanner/quintic_polynomials_planner.py
@@ -111,7 +111,10 @@ def quintic_polynomials_planner(sx, sy, syaw, sv, sa, gx, gy, gyaw, gv, ga, max_
 
         time, rx, ry, ryaw, rv, ra, rj = [], [], [], [], [], [], []
 
-        for t in np.arange(0.0, T + dt, dt):
+        # Sample up to T without extrapolating beyond the terminal boundary.
+        # Always include T, even when dt does not divide the duration.
+        sample_times = np.append(np.arange(0.0, T, dt), T)
+        for t in sample_times:
             time.append(t)
             rx.append(xqp.calc_point(t))
             ry.append(yqp.calc_point(t))
diff --git a/tests/test_quintic_polynomials_planner.py b/tests/test_quintic_polynomials_planner.py
index 43f3c6bada..bfda9564db 100644
--- a/tests/test_quintic_polynomials_planner.py
+++ b/tests/test_quintic_polynomials_planner.py
@@ -1,4 +1,6 @@
 import conftest  # Add root path to sys.path
+import numpy as np
+import pytest
 from PathPlanning.QuinticPolynomialsPlanner import quintic_polynomials_planner as m
 
 
@@ -7,5 +9,21 @@ def test1():
     m.main()
 
 
+@pytest.mark.parametrize("dt", [0.5, 0.7, 6.0])
+def test_quintic_trajectory_includes_exact_terminal_time(dt):
+    m.show_animation = False
+    time, rx, ry, ryaw, rv, ra, rj = m.quintic_polynomials_planner(
+        sx=0.0, sy=0.0, syaw=0.0, sv=0.0, sa=0.0,
+        gx=10.0, gy=5.0, gyaw=0.0, gv=0.0, ga=0.0,
+        max_accel=1000.0, max_jerk=1000.0, dt=dt
+    )
+
+    assert time[-1] == m.MIN_T
+    assert np.all(np.diff(time) > 0)
+    assert np.all(np.asarray(time) <= m.MIN_T)
+    assert len({len(values) for values in (time, rx, ry, ryaw, rv, ra, rj)}) == 1
+    np.testing.assert_allclose([rx[-1], ry[-1]], [10.0, 5.0], atol=1e-9)
+
+
 if __name__ == '__main__':
     conftest.run_this_test(__file__)