diff --git a/examples/plugin/custom_sensor_system/CMakeLists.txt b/examples/plugin/custom_sensor_system/CMakeLists.txt
index fee194db7b..58fd5050ba 100644
--- a/examples/plugin/custom_sensor_system/CMakeLists.txt
+++ b/examples/plugin/custom_sensor_system/CMakeLists.txt
@@ -20,7 +20,7 @@ include(FetchContent)
 FetchContent_Declare(
   sensors_clone
   GIT_REPOSITORY https://github.com/gazebosim/gz-sensors
-  GIT_TAG main
+  GIT_TAG gz-sensors${GZ_SENSORS_VER}
 )
 FetchContent_Populate(sensors_clone)
 add_subdirectory(${sensors_clone_SOURCE_DIR}/examples/custom_sensor ${sensors_clone_BINARY_DIR})
diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index 98bbe66650..f7228de0a1 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -105,7 +105,7 @@ if (BUILD_TESTING)
     endif()
 
     set(_env_vars)
-    list(APPEND _env_vars "PYTHONPATH=${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}/python/")
+    list(APPEND _env_vars "PYTHONPATH=${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}/python/:$ENV{PYTHONPATH}")
     list(APPEND _env_vars "LD_LIBRARY_PATH=${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}:$ENV{LD_LIBRARY_PATH}")
     set_tests_properties(${test} PROPERTIES
       ENVIRONMENT "${_env_vars}")
diff --git a/src/systems/multicopter_motor_model/MulticopterMotorModel.cc b/src/systems/multicopter_motor_model/MulticopterMotorModel.cc
index 5a711272bd..02fa87b774 100644
--- a/src/systems/multicopter_motor_model/MulticopterMotorModel.cc
+++ b/src/systems/multicopter_motor_model/MulticopterMotorModel.cc
@@ -411,7 +411,8 @@ void MulticopterMotorModel::PreUpdate(const UpdateInfo &_info,
 
     const auto parentLinkName = _ecm.Component<components::ParentLinkName>(
         this->dataPtr->jointEntity);
-    this->dataPtr->parentLinkName = parentLinkName->Data();
+    if (parentLinkName)
+      this->dataPtr->parentLinkName = parentLinkName->Data();
   }
 
   if (this->dataPtr->linkEntity == kNullEntity)
diff --git a/src/systems/optical_tactile_plugin/OpticalTactilePlugin.cc b/src/systems/optical_tactile_plugin/OpticalTactilePlugin.cc
index e2bf376e1e..92320f0de3 100644
--- a/src/systems/optical_tactile_plugin/OpticalTactilePlugin.cc
+++ b/src/systems/optical_tactile_plugin/OpticalTactilePlugin.cc
@@ -632,7 +632,7 @@ void OpticalTactilePluginPrivate::Enable(const gz::msgs::Boolean &_req)
 
   this->enabled = _req.data();
 
-  if (!_req.data())
+  if (!_req.data() && this->visualizePtr)
   {
     this->visualizePtr->RemoveNormalForcesAndContactsMarkers();
   }
diff --git a/test/integration/CMakeLists.txt b/test/integration/CMakeLists.txt
index da422d2a89..df28287316 100644
--- a/test/integration/CMakeLists.txt
+++ b/test/integration/CMakeLists.txt
@@ -246,5 +246,5 @@ endif()
 
 if (TARGET INTEGRATION_python_system_loader)
   set_tests_properties(INTEGRATION_python_system_loader PROPERTIES
-    ENVIRONMENT "PYTHONPATH=${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}/python/")
+    ENVIRONMENT "PYTHONPATH=${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}/python/:$ENV{PYTHONPATH}")
 endif()