diff --git a/src/game-logic/game-logic.service.ts b/src/game-logic/game-logic.service.ts
index b37c55b..10f8359 100644
--- a/src/game-logic/game-logic.service.ts
+++ b/src/game-logic/game-logic.service.ts
@@ -56,6 +56,7 @@ export class GameLogicService {
       homeSystem.population = empire.resources.population;
       homeSystem.upgrade = 'upgraded';
       homeSystem.capacity *= SYSTEM_UPGRADES.upgraded.capacity_multiplier;
+      homeSystem.health = SYSTEM_UPGRADES.upgraded.health;
       if (member?.empire?.homeSystem) {
         homeSystem.type = member.empire.homeSystem;
       }
@@ -176,6 +177,8 @@ export class GameLogicService {
       this.processDistricts(system, systemUpkeepPaid, popCoverage, empire, systemVariables, aggregates);
       this.processBuildings(system, systemUpkeepPaid, popCoverage, empire, systemVariables, aggregates);
 
+      this.healSystem(system, empire, systemVariables);
+
       this.deductJoblessUpkeep(system, empire, systemVariables, aggregates);
 
       if (popUpkeepPaid) {
@@ -293,6 +296,14 @@ export class GameLogicService {
     }
   }
 
+  private healSystem(system: SystemDocument, empire: EmpireDocument, variables: Record<Variable, number>) {
+    const maxHealth = this.systemLogicService.maxHealthOrDefense(system, empire, 'health', variables);
+    if (system.health < maxHealth) {
+      const healingRate = 0.1;
+      system.health = Math.min(maxHealth, system.health + healingRate * maxHealth);
+    }
+  }
+
   private deductJoblessUpkeep(system: SystemDocument, empire: EmpireDocument, variables: Record<Variable, number>, aggregates?: Partial<Record<ResourceName, AggregateResult>>) {
     const totalJobs = this.getJobs(system);
     const joblessPops = system.population - totalJobs;
diff --git a/src/system/system-logic.service.ts b/src/system/system-logic.service.ts
index 9991de1..d5b32b4 100644
--- a/src/system/system-logic.service.ts
+++ b/src/system/system-logic.service.ts
@@ -203,7 +203,7 @@ export class SystemLogicService {
     }
 
     const baseValue = relevantVariables[upgradeVariable];
-    const fortressCount = system.buildings.filter(b => b === 'fortress').length;
+    const fortressCount = system.buildings.countIf(b => b === 'fortress');
     const fortressBonus = fortressCount * relevantVariables[fortressVariable];
     const total = baseValue + fortressBonus;
     if (aggregate) {