diff --git a/src/main/java/Plate.java b/src/main/java/Plate.java
index aae0a07..3bdc713 100644
--- a/src/main/java/Plate.java
+++ b/src/main/java/Plate.java
@@ -25,6 +25,7 @@ public class Plate {
         this.cells = cells;
         this.sourceFile = cellFilename;
         this.size = numWells;
+        this.wells = new ArrayList<>();
         this.error = dropoutRate;
         this.populations = populations;
         this.exponential = exponential;