diff --git a/mujoco_maze/maze_env.py b/mujoco_maze/maze_env.py
index be8d42f..2164e5a 100644
--- a/mujoco_maze/maze_env.py
+++ b/mujoco_maze/maze_env.py
@@ -95,7 +95,7 @@ class MazeEnv(gym.Env):
             # Increase initial z-pos of ant.
             height_offset = height * size_scaling
             torso = tree.find(".//body[@name='torso']")
-            torso.set("pos", f"0 0 {0.75 + height_offset:%.2f}")
+            torso.set("pos", f"0 0 {0.75 + height_offset:.2f}")
         if self.blocks:
             # If there are movable blocks, change simulation settings to perform
             # better contact detection.