diff --git a/CHANGELOG.md b/CHANGELOG.md
index 926ecb00..709436f5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,8 @@ will consitute of a breaking change warranting a new major release:
 
 - TMP1075: Set dataset invalid on shutdown explicitely
 - Small fixes for TMP1075 FDIR: Use strange and missed reply counters.
+- TCS controller: Last heater (S-band heater) was skipped for transition completion
+  checks.
 - TCS controller: A helper member to track the elapsed heater control cycles was not reset
   properly, which could lead to switch transitions being completed immediately. This can
   lead to weird bugs like heaters being commanded ON twice and can potentially lead to
diff --git a/mission/controller/ThermalController.cpp b/mission/controller/ThermalController.cpp
index a235e707..79f11785 100644
--- a/mission/controller/ThermalController.cpp
+++ b/mission/controller/ThermalController.cpp
@@ -1753,7 +1753,7 @@ void ThermalController::resetSensorsArray() {
 }
 
 void ThermalController::heaterTransitionControl(const HeaterSwitchStates& currentHeaterStates) {
-  for (unsigned i = 0; i < 7; i++) {
+  for (unsigned i = 0; i < heater::Switch::NUMBER_OF_SWITCHES; i++) {
     if (heaterStates[i].switchTransition) {
       if (currentHeaterStates[i] == heaterStates[i].target) {
         heaterStates[i].switchTransition = false;