1 files changed, 9 insertions, 4 deletions
diff --git a/src/main/java/sevenUnits/unit/UnitDatabase.java b/src/main/java/sevenUnits/unit/UnitDatabase.java
index dc81aca..690430b 100644
--- a/src/main/java/sevenUnits/unit/UnitDatabase.java
+++ b/src/main/java/sevenUnits/unit/UnitDatabase.java
@@ -1905,18 +1905,23 @@ public final class UnitDatabase {
 	 *
 	 * @since 2024-08-22
 	 */
-	private List<LinearUnit> getUnitSetFromExpression(String expression) {
+	List<LinearUnit> getUnitSetFromExpression(String expression) {
 		final String[] parts = expression.split(";");
 		final List<LinearUnit> units = new ArrayList<>(parts.length);
 		for (final String unitName : parts) {
 			final Unit unit = this.getUnitFromExpression(unitName.trim());
 			
-			if (unit instanceof LinearUnit) {
-				units.add((LinearUnit) unit);
-			} else
+			if (!(unit instanceof LinearUnit)) {
 				throw new IllegalArgumentException(String.format(
 						"Unit '%s' is in a unit-set expression, but is not linear.",
 						unitName));
+			} else if (units.size() > 0 && !unit.canConvertTo(units.get(0))) {
+				throw new IllegalArgumentException(String.format(
+						"Units in expression '%s' have different dimensions.",
+						expression));
+			}
+
+			units.add((LinearUnit) unit);
 		}
 		return units;
 	}