Index: firmware/App/Services/Messaging.c
===================================================================
diff -u -rf40a7a70ad79b1dfba9d3b19887326d0a923a775 -r253b31257a3b6877624e8b83ee06c1404c1c3dd5
--- firmware/App/Services/Messaging.c	(.../Messaging.c)	(revision f40a7a70ad79b1dfba9d3b19887326d0a923a775)
+++ firmware/App/Services/Messaging.c	(.../Messaging.c)	(revision 253b31257a3b6877624e8b83ee06c1404c1c3dd5)
@@ -128,6 +128,7 @@
     { MSG_ID_DD_PRESSURE_SENSOR_PUBLISH_INTERVAL_OVERRIDE_REQUEST,                  &testDDPressureSensorDataPublishIntervalOverride },
     { MSG_ID_DD_PRESSURE_SENSOR_FILTER_READINGS_OVERRIDE_REQUEST,                   &testDDPressureSensorFilteredReadingsOverride },
     { MSG_ID_DD_PRESSURE_SENSOR_FILTER_TEMPERATURE_OVERRIDE_REQUEST,                &testDDPressureSensorFilteredTemperatureReadingsOverride },
+#ifndef __TEENSY_CONDUCTIVITY_DRIVER__
     { MSG_ID_DD_CONDUCTIVITY_SENSOR_READINGS_OVERRIDE_REQUEST,                      &testDDConductivitySensorReadingsOverride },
     { MSG_ID_DD_CONDUCTIVITY_SENSOR_TEMPERATURE_OVERRIDE_REQUEST,                   &testDDConductivitySensorTemperatureReadingsOverride },
     { MSG_ID_DD_CONDUCTIVITY_SENSOR_READ_COUNTER_OVERRIDE_REQUEST,                  &testDDConductivitySensorReadCounterOverride },
@@ -138,6 +139,7 @@
     { MSG_ID_FP_CONDUCTIVITY_TEMP_OVERRIDE_REQUEST,                                 &testFPConductivitySensorTemperatureReadingsOverride },
     { MSG_ID_FP_CONDUCTIVITY_READ_COUNT_OVERRIDE_REQUEST,                           &testFPConductivitySensorReadCounterOverride },
     { MSG_ID_FP_CONDUCTIVITY_ERROR_COUNT_OVERRIDE_REQUEST,                          &testFPConductivitySensorErrorCounterOverride },
+#endif
     { MSG_ID_DD_CONCENTRATE_PUMP_PUBLISH_INTERVAL_OVERRIDE_REQUEST,                 &testConcentratePumpDataPublishIntervalOverride },
     { MSG_ID_DD_CONCENTRATE_PUMP_TARGET_SPEED_OVERRIDE_REQUEST,                     &testConcentratePumpTargetSpeedOverride },
     { MSG_ID_DD_CONCENTRATE_PUMP_MEASURED_SPEED_OVERRIDE_REQUEST,                   &testConcentratePumpMeasuredSpeedOverride },