diff --git a/dgp/utils/structures/key_line_3d.py b/dgp/utils/structures/key_line_3d.py
index 694ce4c..787b626 100644
--- a/dgp/utils/structures/key_line_3d.py
+++ b/dgp/utils/structures/key_line_3d.py
@@ -95,6 +95,6 @@ def to_proto(self):
             As defined in `proto/annotations.proto`
         """
         return [
-            annotations_pb2.KeyPoint3D(x=int(self.x[j]), y=int(self.y[j]), z=int(self.z[j]))
+            annotations_pb2.KeyPoint3D(x=float(self.x[j]), y=float(self.y[j]), z=float(self.z[j]))
             for j, _ in enumerate(self.x)
         ]