diff --git a/OpenNest.Engine/BestFit/NfpSlideStrategy.cs b/OpenNest.Engine/BestFit/NfpSlideStrategy.cs
index e5426f9..f5dc2fb 100644
--- a/OpenNest.Engine/BestFit/NfpSlideStrategy.cs
+++ b/OpenNest.Engine/BestFit/NfpSlideStrategy.cs
@@ -20,6 +20,10 @@ namespace OpenNest.Engine.BestFit
         public List<PairCandidate> GenerateCandidates(Drawing drawing, double spacing, double stepSize)
         {
             var candidates = new List<PairCandidate>();
+
+            if (stepSize <= 0)
+                return candidates;
+
             var halfSpacing = spacing / 2;
 
             // Extract stationary polygon (Part1 at rotation 0), with spacing applied.