diff --git a/src/main/java/cz/cvut/fel/sit/omo/foodchain/product/Product.java b/src/main/java/cz/cvut/fel/sit/omo/foodchain/product/Product.java
index 6252afd..9feee01 100644
--- a/src/main/java/cz/cvut/fel/sit/omo/foodchain/product/Product.java
+++ b/src/main/java/cz/cvut/fel/sit/omo/foodchain/product/Product.java
@@ -71,11 +71,16 @@ public class Product
     // "State machine methods"
 
     /**
-     * Set current product state to AVAILABLE
+     * Set current product state to AVAILABLE. Throws IllegalStateException if the product is not IN_ACTION, READY_FOR_RECEPTION or IN_REQUIREMENT.
      */
     public void setStateToAvailable()
     {
-        this.productState = ProductState.AVAILABLE;
+        if (this.productState.equals(ProductState.IN_ACTION) ||
+                this.productState.equals(ProductState.READY_FOR_RECEPTION) ||
+                this.productState.equals(ProductState.IN_REQUIREMENT))
+            this.productState = ProductState.AVAILABLE;
+        else
+            throw new IllegalStateException("Cannot set state AVAILABLE. Product is not IN_ACTION, READY_FOR_RECEPTION or IN_REQUIREMENT");
     }
 
     /**
diff --git a/src/main/java/cz/cvut/fel/sit/omo/foodchain/product/ProductState.java b/src/main/java/cz/cvut/fel/sit/omo/foodchain/product/ProductState.java
index 906282e..7e4be38 100644
--- a/src/main/java/cz/cvut/fel/sit/omo/foodchain/product/ProductState.java
+++ b/src/main/java/cz/cvut/fel/sit/omo/foodchain/product/ProductState.java
@@ -2,5 +2,5 @@ package cz.cvut.fel.sit.omo.foodchain.product;
 
 public enum ProductState
 {
-    AVAILABLE, READY_FOR_DISPATCH, IN_TRANSIT, READY_FOR_RECEPTION, IN_ACTION
+    AVAILABLE, READY_FOR_DISPATCH, IN_TRANSIT, READY_FOR_RECEPTION, IN_ACTION, IN_REQUIREMENT
 }