diff --git a/gym_ignition_models/ground_plane/ground_plane.sdf b/gym_ignition_models/ground_plane/ground_plane.sdf
index d77c1ac..c02c8a7 100644
--- a/gym_ignition_models/ground_plane/ground_plane.sdf
+++ b/gym_ignition_models/ground_plane/ground_plane.sdf
@@ -12,7 +12,6 @@
                     <friction>
                         <ode>
                             <mu>100</mu>
-                            <mu2>50</mu2>
                         </ode>
                     </friction>
                 </surface>
diff --git a/gym_ignition_models/iCubGazeboSimpleCollisionsV2_5/icub_simple_collisions.urdf b/gym_ignition_models/iCubGazeboSimpleCollisionsV2_5/icub_simple_collisions.urdf
index 052cb25..04a04d4 100644
--- a/gym_ignition_models/iCubGazeboSimpleCollisionsV2_5/icub_simple_collisions.urdf
+++ b/gym_ignition_models/iCubGazeboSimpleCollisionsV2_5/icub_simple_collisions.urdf
@@ -1552,6 +1552,11 @@
         <contact>
           <collide_bitmask>294</collide_bitmask>
         </contact>
+        <friction>
+          <ode>
+            <mu>1</mu>
+          </ode>
+        </friction>
       </surface>
     </collision>
   </gazebo>
@@ -1706,6 +1711,11 @@
         <contact>
           <collide_bitmask>198</collide_bitmask>
         </contact>
+        <friction>
+          <ode>
+            <mu>1</mu>
+          </ode>
+        </friction>
       </surface>
     </collision>
   </gazebo>