diff --git a/game-app/game-core/src/main/java/games/strategy/triplea/attachments/UnitAttachment.java b/game-app/game-core/src/main/java/games/strategy/triplea/attachments/UnitAttachment.java
index d091731cf22..1d95388c04f 100644
--- a/game-app/game-core/src/main/java/games/strategy/triplea/attachments/UnitAttachment.java
+++ b/game-app/game-core/src/main/java/games/strategy/triplea/attachments/UnitAttachment.java
@@ -2516,7 +2516,12 @@ private Tuple<Integer, String> parseStackingLimit(final String type, final Strin
     return Tuple.of(max, s[1].intern());
   }
 
-  private void setTuv(final String s) {
+  private void setTuv(final String s) throws GameParseException {
+    final int value = getInt(s);
+    if (value < -1) {
+      throw new GameParseException(
+          "tuv must be 0 positive (or -1, default, to calculate) " + thisErrorMsg());
+    }
     tuv = getInt(s);
   }
 
diff --git a/game-app/game-core/src/main/java/games/strategy/triplea/util/TuvCostsCalculator.java b/game-app/game-core/src/main/java/games/strategy/triplea/util/TuvCostsCalculator.java
index cbaab966851..dd5c4468d01 100644
--- a/game-app/game-core/src/main/java/games/strategy/triplea/util/TuvCostsCalculator.java
+++ b/game-app/game-core/src/main/java/games/strategy/triplea/util/TuvCostsCalculator.java
@@ -120,7 +120,7 @@ private static IntegerMap<UnitType> getCostsForTuvForAllPlayersMergedAndAveraged
     // Add any units that have XML TUV even if they aren't purchasable
     for (final UnitType unitType : data.getUnitTypeList()) {
       final UnitAttachment ua = unitType.getUnitAttachment();
-      if (ua.getTuv() > 0) {
+      if (ua.getTuv() > -1) {
         costs.put(unitType, ua.getTuv());
       }
     }
@@ -131,7 +131,7 @@ private static IntegerMap<UnitType> getCostsForTuvForAllPlayersMergedAndAveraged
   private static int getTotalTuv(
       final UnitType unitType, final IntegerMap<UnitType> costs, final Set<UnitType> alreadyAdded) {
     final UnitAttachment ua = unitType.getUnitAttachment();
-    if (ua.getTuv() > 0) {
+    if (ua.getTuv() > -1) {
       return ua.getTuv();
     }
     int tuv = costs.getInt(unitType);