diff --git a/pom.xml b/pom.xml
index 7fa63e5..f6aa0a1 100644
--- a/pom.xml
+++ b/pom.xml
@@ -116,7 +116,7 @@
   	<dependency>
   		<groupId>org.apache.lucene</groupId>
   		<artifactId>lucene-core</artifactId>
-  		<version>7.1.0</version>
+  		<version>5.3.1</version>
   	</dependency>
     <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
     <dependency>