diff --git a/README_TESTED_SENSORS.md b/README_TESTED_SENSORS.md
index 6e03e5eb6..5daa83913 100644
--- a/README_TESTED_SENSORS.md
+++ b/README_TESTED_SENSORS.md
@@ -19,8 +19,11 @@ However, often only one value is provided.
 ### Speed
 
 * Garmin Speed Sensor 2
-  This sensor reports speed data as cadence.
-  A workaround is in place.
+  * Has updatable firmware that requires an account for garmin.com
+  * This sensor reports speed data as cadence.
+    A workaround is in place.
+  * This sensor sometimes counts backwards (unknown software version).
+    A workaround is in place.
 
 * Wahoo Speed (Model: WFRPMSPD)
 
diff --git a/src/main/java/de/dennisguse/opentracks/content/sensor/SensorDataCycling.java b/src/main/java/de/dennisguse/opentracks/content/sensor/SensorDataCycling.java
index 2c3a94e00..6b3cfb43a 100644
--- a/src/main/java/de/dennisguse/opentracks/content/sensor/SensorDataCycling.java
+++ b/src/main/java/de/dennisguse/opentracks/content/sensor/SensorDataCycling.java
@@ -127,6 +127,8 @@ public final class SensorDataCycling {
                     value = null;
                 } else {
                     long wheelDiff = UintUtils.diff(wheelRevolutionsCount, previous.wheelRevolutionsCount, UintUtils.UINT16_MAX);
+                    wheelDiff = Math.abs(wheelDiff); //HACK for Garmin Speed 2 as it some of those seem to count backwards
+
                     double timeDiff_s = timeDiff_ms * UnitConversions.MS_TO_S;
                     float distance_m = (float) (wheelDiff * wheel_circumference_mm * UnitConversions.MM_TO_M);
                     float distance_overall_m = distance_m;