diff --git a/examples/bilingual_dictionaries/vsms1.xml b/examples/bilingual_dictionaries/vsms1.xml
index 93c6067..76ae7c0 100644
--- a/examples/bilingual_dictionaries/vsms1.xml
+++ b/examples/bilingual_dictionaries/vsms1.xml
@@ -4,7 +4,7 @@
     <head>
       <status>AE</status>
       <headword>
-        <lemma audio="audio-3132">bolnišnica</lemma>
+        <lemma audio="audio-3132" type="single">bolnišnica</lemma>
         <homonymy>
           <homonymyFeature name="pronunciation">bolníšnica</homonymyFeature>
           <homonymyFeature name="blahblah">xyz</homonymyFeature>
diff --git a/resources/schema/inventory.xsd b/resources/schema/inventory.xsd
index 207c6ea..17a7cdb 100644
--- a/resources/schema/inventory.xsd
+++ b/resources/schema/inventory.xsd
@@ -11,6 +11,15 @@
     <xsd:simpleContent>
       <xsd:extension base="xsd:string">
         <xsd:attribute name="audio" type="xsd:string"/>
+        <xsd:attribute name="type">
+          <xsd:simpleType>
+            <xsd:restriction base="xsd:string">
+              <xsd:enumeration value="single"/>
+              <xsd:enumeration value="phrase"/>
+              <xsd:enumeration value="compound"/>
+            </xsd:restriction>
+          </xsd:simpleType>
+        </xsd:attribute>
       </xsd:extension>
     </xsd:simpleContent>
   </xsd:complexType>
