diff --git a/ApplicationCode/ProjectDataModel/RimWellLogExtractionCurve.cpp b/ApplicationCode/ProjectDataModel/RimWellLogExtractionCurve.cpp
index 76c63131ab..0ad3a4f267 100644
--- a/ApplicationCode/ProjectDataModel/RimWellLogExtractionCurve.cpp
+++ b/ApplicationCode/ProjectDataModel/RimWellLogExtractionCurve.cpp
@@ -363,7 +363,7 @@ void RimWellLogExtractionCurve::validCurvePointIntervals(const std::vector<doubl
         }
     }
 
-    if (validDepthStartIdx > 0 && validDepthStartIdx < valuesCount)
+    if (validDepthStartIdx >= 0 && validDepthStartIdx < valuesCount)
     {
         validDepthIntervals.push_back(std::make_pair(validDepthStartIdx, valuesCount - 1));
     }