diff --git a/core/src/main/resources/store/trader.xsd b/core/src/main/resources/store/trader.xsd
index 881ffbf..25fe6a6 100644
--- a/core/src/main/resources/store/trader.xsd
+++ b/core/src/main/resources/store/trader.xsd
@@ -29,7 +29,7 @@
 
     <xs:complexType name="vendorType" mixed="true">
         <xs:sequence>
-            <xs:element name="offer" type="offerType" maxOccurs="unbounded"/>
+            <xs:element name="offer" type="offerType" minOccurs="0" maxOccurs="unbounded"/>
         </xs:sequence>
         <xs:attribute name="name" type="xs:string" use="required"/>
         <xs:attribute name="x" type="xs:double" use="optional"/>
diff --git a/core/src/test/resources/test.xml b/core/src/test/resources/test.xml
index 21e14e8..691b0a6 100644
--- a/core/src/test/resources/test.xml
+++ b/core/src/test/resources/test.xml
@@ -12,5 +12,8 @@
         <vendor name="Vendor 1">
             <offer item="i1" type="SELL" price="140"/>
         </vendor>
+
+        <vendor name="Empty system" x="1" y="2" z="3"/>
+
     </vendors>
 </market>
\ No newline at end of file