diff --git a/CHANGELOG.md b/CHANGELOG.md
index 213699b3..74a634e6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,11 @@ will consitute of a breaking change warranting a new major release:
 
 # [unreleased]
 
+## Fixed
+
+- As the `STR Handler` does not set an untrustworthy quaternion to invalid, the `ACS Controller`
+  needs to do this on its own.
+
 # [v7.5.2] 2023-12-14
 
 ## Fixed
diff --git a/mission/controller/AcsController.cpp b/mission/controller/AcsController.cpp
index 6adb4a0b..54d96699 100644
--- a/mission/controller/AcsController.cpp
+++ b/mission/controller/AcsController.cpp
@@ -380,8 +380,10 @@ void AcsController::performDetumble() {
 }
 
 void AcsController::performPointingCtrl() {
-  bool strValid = (sensorValues.strSet.caliQw.isValid() and sensorValues.strSet.caliQx.isValid() and
-                   sensorValues.strSet.caliQy.isValid() and sensorValues.strSet.caliQz.isValid());
+  bool strValid =
+      ((sensorValues.strSet.caliQw.isValid() and sensorValues.strSet.caliQx.isValid() and
+        sensorValues.strSet.caliQy.isValid() and sensorValues.strSet.caliQz.isValid()) and
+       (sensorValues.strSet.isTrustWorthy.isValid() and sensorValues.strSet.isTrustWorthy.value));
   uint8_t useMekf = false;
   switch (mode) {
     case acs::PTG_IDLE:
diff --git a/mission/controller/acs/FusedRotationEstimation.cpp b/mission/controller/acs/FusedRotationEstimation.cpp
index b4d0f0c4..758004d2 100644
--- a/mission/controller/acs/FusedRotationEstimation.cpp
+++ b/mission/controller/acs/FusedRotationEstimation.cpp
@@ -73,8 +73,10 @@ void FusedRotationEstimation::estimateFusedRotationRate(
 void FusedRotationEstimation::estimateFusedRotationRateStr(
     ACS::SensorValues *sensorValues, const double timeDelta,
     acsctrl::FusedRotRateSourcesData *fusedRotRateSourcesData) {
-  if (not(sensorValues->strSet.caliQw.isValid() and sensorValues->strSet.caliQx.isValid() and
-          sensorValues->strSet.caliQy.isValid() and sensorValues->strSet.caliQz.isValid())) {
+  if (not((sensorValues->strSet.caliQw.isValid() and sensorValues->strSet.caliQx.isValid() and
+           sensorValues->strSet.caliQy.isValid() and sensorValues->strSet.caliQz.isValid()) and
+          (sensorValues->strSet.isTrustWorthy.isValid() and
+           sensorValues->strSet.isTrustWorthy.value))) {
     {
       PoolReadGuard pg(fusedRotRateSourcesData);
       if (pg.getReadResult() == returnvalue::OK) {