diff --git a/VectoCore/VectoCore/InputData/Reader/FullLoadCurveReader.cs b/VectoCore/VectoCore/InputData/Reader/FullLoadCurveReader.cs
index 5276b5372d50e74787d1be2cff5f2e5947599237..e0b5b5b5bc8967b42a7697d2a8947e1c9b5e48a4 100644
--- a/VectoCore/VectoCore/InputData/Reader/FullLoadCurveReader.cs
+++ b/VectoCore/VectoCore/InputData/Reader/FullLoadCurveReader.cs
@@ -84,6 +84,12 @@ namespace TUGraz.VectoCore.InputData.Reader
 				tmp = data.Columns.Count > 3 ? new PT1(data) : new PT1();
 			}
 			entriesFld.Sort((entry1, entry2) => entry1.EngineSpeed.Value().CompareTo(entry2.EngineSpeed.Value()));
+			var duplicates = entriesFld.Select(x => x.EngineSpeed.AsRPM).GroupBy(x => x).Where(g => g.Count() > 1)
+										.Select(g => g.Key).ToList();
+			if (duplicates.Count > 0) {
+				throw new VectoException(
+					"Error reading full-load curve: multiple entries for engine speeds {0}", string.Join(", ", duplicates));
+			}
 			return new EngineFullLoadCurve(entriesFld, tmp);
 		}