diff --git a/libraries/shared/src/AtRestDetector.cpp b/libraries/shared/src/AtRestDetector.cpp
index d790e2b066..4c08b30dcd 100644
--- a/libraries/shared/src/AtRestDetector.cpp
+++ b/libraries/shared/src/AtRestDetector.cpp
@@ -32,7 +32,7 @@ void AtRestDetector::reset(const glm::vec3& startPosition, const glm::quat& star
 
 bool AtRestDetector::update(const glm::vec3& position, const glm::quat& rotation) {
     uint64_t now = usecTimestampNow();
-    float dt = (float)(_lastUpdateTime - now) / (float)USECS_PER_SECOND;
+    float dt = (float)(now - _lastUpdateTime) / (float)USECS_PER_SECOND;
     _lastUpdateTime = now;
     const float TAU = 1.0f;
     float delta = glm::min(dt / TAU, 1.0f);