diff --git a/CHANGELOG.md b/CHANGELOG.md
index fe4c44f9..69706abb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ will consitute of a breaking change warranting a new major release:
 ## Fixed
 
 - Faulty mapping of input values for QUEST algorithm.
+- Fixed validity check for QUEST algorithm.
 
 # [v7.5.0] 2023-12-06
 
diff --git a/mission/controller/acs/AttitudeEstimation.cpp b/mission/controller/acs/AttitudeEstimation.cpp
index 5e07642f..95a4046d 100644
--- a/mission/controller/acs/AttitudeEstimation.cpp
+++ b/mission/controller/acs/AttitudeEstimation.cpp
@@ -8,14 +8,14 @@ AttitudeEstimation::~AttitudeEstimation() {}
 
 void AttitudeEstimation::quest(acsctrl::SusDataProcessed *susData,
                                acsctrl::MgmDataProcessed *mgmData,
-                               acsctrl::AttitudeEstimationData *attitudeEstimation) {
+                               acsctrl::AttitudeEstimationData *attitudeEstimationData) {
   if (not(susData->susVecTot.isValid() and susData->sunIjkModel.isValid() and
-          mgmData->mgmVecTot.value and mgmData->magIgrfModel.isValid())) {
+          mgmData->mgmVecTot.isValid() and mgmData->magIgrfModel.isValid())) {
     {
-      PoolReadGuard pg{attitudeEstimation};
+      PoolReadGuard pg{attitudeEstimationData};
       if (pg.getReadResult() == returnvalue::OK) {
-        std::memcpy(attitudeEstimation->quatQuest.value, ZERO_VEC4, 4 * sizeof(double));
-        attitudeEstimation->quatQuest.setValid(false);
+        std::memcpy(attitudeEstimationData->quatQuest.value, ZERO_VEC4, 4 * sizeof(double));
+        attitudeEstimationData->quatQuest.setValid(false);
       }
     }
     return;
@@ -102,10 +102,10 @@ void AttitudeEstimation::quest(acsctrl::SusDataProcessed *susData,
     QuaternionOperations::slerp(qBI, qOld, acsParameters->onBoardParams.questFilterWeight, qBI);
   }
   {
-    PoolReadGuard pg{attitudeEstimation};
+    PoolReadGuard pg{attitudeEstimationData};
     if (pg.getReadResult() == returnvalue::OK) {
-      std::memcpy(attitudeEstimation->quatQuest.value, qBI, 4 * sizeof(double));
-      attitudeEstimation->quatQuest.setValid(true);
+      std::memcpy(attitudeEstimationData->quatQuest.value, qBI, 4 * sizeof(double));
+      attitudeEstimationData->quatQuest.setValid(true);
     }
   }
 }