diff --git a/Migration.md b/Migration.md
index 68fd79fb0..65fea3e8c 100644
--- a/Migration.md
+++ b/Migration.md
@@ -14,6 +14,9 @@ release will remove the deprecated code.
 1. Header files under `ignition/...` are deprecated and will be removed in future versions.
    Use `gz/...` instead.
 
+1. The shared libraries have `gz` where there used to be `ignition`.
+  1. Using the un-migrated version is still possible due to tick-tocks, but will be removed in future versions.
+
 1. The following `IGN_` / `IGNITION_` prefixed macros are deprecated and will be removed in future versions.
    Additionally, they will only be available when including the corresponding `ignition/...` header.
    Use the `GZ_` prefix instead.
@@ -26,6 +29,8 @@ release will remove the deprecated code.
    1. `IGNITION_PHYSICS_CONST_GET_ERROR` (hard-tocked, inside detail header)
    1. `IGNITION_UNITTEST_EXPECTDATA_ACCESS` (hard-tocked, inside test and detail headers)
    1. `IGNITION_PHYSICS_DEFINE_COORDINATE_SPACE` (hard-tocked, inside detail header)
+1. The `ignition:expressed_in` SDF attribute is deprecated and will be removed.
+   Please use `gz:expressed_in` instead.
 
 ### Breaking Changes
 
diff --git a/dartsim/src/SDFFeatures.cc b/dartsim/src/SDFFeatures.cc
index d066fb41e..628489f70 100644
--- a/dartsim/src/SDFFeatures.cc
+++ b/dartsim/src/SDFFeatures.cc
@@ -829,12 +829,26 @@ Identity SDFFeatures::ConstructSdfCollision(
       math::Vector3d fdir1 = frictionDirectionElem->Get<math::Vector3d>();
       aspect->setFirstFrictionDirection(math::eigen3::convert(fdir1));
 
-      const std::string kExpressedIn = "ignition:expressed_in";
-      if (frictionDirectionElem->HasAttribute(kExpressedIn))
+      std::string expressedIn = "gz:expressed_in";
+
+      // TODO(CH3): Deprecated. Remove on tock.
+      // Try deprecated ignition:expressed_in attribute
+      // if gz:expressed_in attribute is missing
+      if (!frictionDirectionElem->HasAttribute("gz:expressed_in"))
+      {
+        if (frictionDirectionElem->HasAttribute("ignition:expressed_in"))
+        {
+          gzwarn << "The `ignition:expressed_in` attribute is deprecated. "
+                 << "Please use `gz:expressed_in` instead." << std::endl;
+          expressedIn = "ignition:expressed_in";
+        }
+      }
+
+      if (frictionDirectionElem->HasAttribute(expressedIn))
       {
         auto skeleton = bn->getSkeleton();
         auto directionFrameBodyNode = skeleton->getBodyNode(
-          frictionDirectionElem->Get<std::string>(kExpressedIn));
+          frictionDirectionElem->Get<std::string>(expressedIn));
         if (nullptr != directionFrameBodyNode)
         {
           aspect->setFirstFrictionDirectionFrame(directionFrameBodyNode);
diff --git a/dartsim/worlds/falling.world b/dartsim/worlds/falling.world
index b3e2d9283..1d2ea2f43 100644
--- a/dartsim/worlds/falling.world
+++ b/dartsim/worlds/falling.world
@@ -2,8 +2,8 @@
 <sdf version="1.6">
   <world name="default">
     <plugin
-      filename="libgz-sim-physics-system.so"
-      name="gz::gazebo::systems::v0::Physics">
+      filename="gz-sim-physics-system"
+      name="gz::sim::systems::v0::Physics">
     </plugin>
     <model name="sphere">
       <pose>0 0 2 0 0.78539816339 0</pose>
diff --git a/tutorials/04-switching-physics-engines.md b/tutorials/04-switching-physics-engines.md
index 83c9d8326..866c52aa0 100644
--- a/tutorials/04-switching-physics-engines.md
+++ b/tutorials/04-switching-physics-engines.md
@@ -86,7 +86,7 @@ gz sim --physics-engine CustomEngine
 ### From C++ API
 
 All features available through the command line are also available through
-[gz::gazebo::ServerConfig](https://gazebosim.org/api/gazebo/4.0/classignition_1_1gazebo_1_1ServerConfig.html).
+[gz::sim::ServerConfig](https://gazebosim.org/api/gazebo/4.0/classignition_1_1gazebo_1_1ServerConfig.html).
 When instantiating a server programmatically, a physics engine can be passed to
 the constructor, for example: