diff --git a/solr/vufind/biblio/conf/schema.xml b/solr/vufind/biblio/conf/schema.xml
index 62baf5555f963fb8f886d473f2de33d9309de55b..29842cbea39f37c937437d34a58af455c0199ffb 100644
--- a/solr/vufind/biblio/conf/schema.xml
+++ b/solr/vufind/biblio/conf/schema.xml
@@ -84,7 +84,7 @@
         <tokenizer class="solr.PatternTokenizerFactory" pattern="^(\S*)\s*.*$" group="1"/>
         <filter class="solr.LowerCaseFilterFactory"/>
         <filter class="solr.PatternReplaceFilterFactory" pattern="[^0-9x]" replacement="" replace="all"/>
-        <filter class="solr.LengthFilterFactory" min="1" max="100" />
+        <filter class="solr.LengthFilterFactory" min="4" max="100" />
       </analyzer>
     </fieldType>
     <!-- case-insensitive/whitespace-agnostic field type for callnumber searching -->