diff --git a/Dockerfile b/Dockerfile
index c6eaca9..c98ebf8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # Ubuntu-based Solr container
-FROM solr:6.4
+FROM solr:6.6
 
 ENV SOLR_HOME=/opt/solr/solr-config/ehri
 
diff --git a/pom.xml b/pom.xml
index 43253e4..ef4d170 100644
--- a/pom.xml
+++ b/pom.xml
@@ -14,7 +14,7 @@
     </modules>
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <solr.version>6.4.0</solr.version>
+        <solr.version>6.6.5</solr.version>
     </properties>
 
     <issueManagement>
diff --git a/solr-config/core/conf/schema.xml b/solr-config/core/conf/schema.xml
index 71076b6..95a377c 100644
--- a/solr-config/core/conf/schema.xml
+++ b/solr-config/core/conf/schema.xml
@@ -52,9 +52,9 @@
                 <!-- Remove diacritics and white space tokenizer -->
                 <!-- treat hyphens equal to whitespace during query time -->
                 <filter class="solr.PatternReplaceFilterFactory" pattern="(\-)" replacement=" " replace="all"/>
-                <filter class="solr.WordDelimiterFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="0" catenateNumbers="0" catenateAll="0" splitOnCaseChange="0" splitOnNumerics="0"/>
+                <filter class="solr.WordDelimiterGraphFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="0" catenateNumbers="0" catenateAll="0" splitOnCaseChange="0" splitOnNumerics="0"/>
                 <filter class="solr.StopFilterFactory" ignoreCase="true" words="generic_swl.txt"/>
-                <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
+                <filter class="solr.SynonymGraphFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
                 <filter class="solr.LowerCaseFilterFactory"/>
             </analyzer>
         </fieldType>