diff --git a/manim/mobject/three_d/three_dimensions.py b/manim/mobject/three_d/three_dimensions.py
index 5732ebb98c..b6124f66ab 100644
--- a/manim/mobject/three_d/three_dimensions.py
+++ b/manim/mobject/three_d/three_dimensions.py
@@ -926,6 +926,10 @@ def __init__(
     ):
         self.thickness = thickness
         self.resolution = (2, resolution) if isinstance(resolution, int) else resolution
+
+        start = np.array(start, dtype=np.float64)
+        end = np.array(end, dtype=np.float64)
+
         self.set_start_and_end_attrs(start, end, **kwargs)
         if color is not None:
             self.set_color(color)
@@ -1183,8 +1187,9 @@ def __init__(
             height=height,
             **kwargs,
         )
-        self.cone.shift(end)
-        self.end_point = VectorizedPoint(end)
+        np_end = np.asarray(end, dtype=np.float64)
+        self.cone.shift(np_end)
+        self.end_point = VectorizedPoint(np_end)
         self.add(self.end_point, self.cone)
         self.set_color(color)
 
diff --git a/tests/test_graphical_units/test_threed.py b/tests/test_graphical_units/test_threed.py
index b6079e5e4c..64c003577b 100644
--- a/tests/test_graphical_units/test_threed.py
+++ b/tests/test_graphical_units/test_threed.py
@@ -164,7 +164,7 @@ def param_surface(u, v):
 
 
 def test_get_start_and_end_Arrow3d():
-    start, end = ORIGIN, np.array([2, 1, 0])
+    start, end = ORIGIN, np.array([2, 1, 0], dtype=np.float64)
     arrow = Arrow3D(start, end)
     assert np.allclose(
         arrow.get_start(), start, atol=0.01
@@ -172,3 +172,19 @@ def test_get_start_and_end_Arrow3d():
     assert np.allclose(
         arrow.get_end(), end, atol=0.01
     ), "end points of Arrow3D do not match"
+
+
+def test_type_conversion_in_Line3D():
+    start, end = [0, 0, 0], [1, 1, 1]
+    line = Line3D(start, end)
+    type_table = [type(item) for item in [*line.get_start(), *line.get_end()]]
+    bool_table = [t == np.float64 for t in type_table]
+    assert all(bool_table), "Types of start and end points are not np.float64"
+
+
+def test_type_conversion_in_Arrow3D():
+    start, end = [0, 0, 0], [1, 1, 1]
+    line = Arrow3D(start, end)
+    type_table = [type(item) for item in [*line.get_start(), *line.get_end()]]
+    bool_table = [t == np.float64 for t in type_table]
+    assert all(bool_table), "Types of start and end points are not np.float64"