diff --git a/.gitignore b/.gitignore
index 5a11e10..5cce705 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,6 +17,7 @@
 /misc/web-api.md
 *~
 .*
+*\#
 !.github
 !.gitignore
 # /src/main/resources/
diff --git a/Changes b/Changes
index f2dd94e..69c85d5 100644
--- a/Changes
+++ b/Changes
@@ -1,3 +1,6 @@
+0.59.4 2021-07-27
+    - [cleanup] Upgrade dependencies (diewald)
+
 0.59.3 2021-06-28
     - [feature] Added "missing query reference" status code (diewald)
     - [cleanup] Added test coverage checking with
diff --git a/pom.xml b/pom.xml
index 76b1a2d..0cc1513 100644
--- a/pom.xml
+++ b/pom.xml
@@ -35,7 +35,7 @@
 
 	<groupId>de.ids_mannheim.korap</groupId>
 	<artifactId>Krill</artifactId>
-	<version>0.59.3</version>
+	<version>0.59.4</version>
 	<packaging>jar</packaging>
 
 	<name>Krill</name>
@@ -43,14 +43,14 @@
 
 	<organization>
 		<name>IDS Mannheim</name>
-		<url>http://www.ids-mannheim.de/</url>
+		<url>https://www.ids-mannheim.de/</url>
 	</organization>
 
 	<developers>
 		<developer>
 			<name>Nils Diewald</name>
 			<email>diewald@ids-mannheim.de</email>
-			<url>http://nils-diewald.de</url>
+			<url>https://www.nils-diewald.de</url>
 		</developer>
 		<developer>
 			<name>Eliza Margaretha</name>
@@ -60,8 +60,11 @@
 
 	<properties>
 	    <java.version>1.8</java.version>
-		<jersey.version>2.15</jersey.version>
-		<jackson.version>[2.9.5,)</jackson.version>
+		<jersey.version>2.34</jersey.version>
+		<jackson.version>2.12.4</jackson.version>
+		<log4j.version>2.14.1</log4j.version>
+                <lucene.version>5.0.0</lucene.version>
+                <cobertura.version>2.7</cobertura.version>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 	</properties>
 
@@ -82,7 +85,7 @@
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
-			<version>4.13.1</version>
+			<version>4.13.2</version>
 			<scope>test</scope>
 		</dependency>
 
@@ -90,42 +93,42 @@
 		<dependency>
 			<groupId>org.apache.logging.log4j</groupId>
 			<artifactId>log4j-api</artifactId>
-			<version>2.13.2</version>
+			<version>${log4j.version}</version>
 		</dependency>
     <dependency>
 			<groupId>org.apache.logging.log4j</groupId>
 			<artifactId>log4j-core</artifactId>
-			<version>2.13.2</version>
+			<version>${log4j.version}</version>
 		</dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-slf4j-impl</artifactId>
-      <version>2.13.2</version>
+      <version>${log4j.version}</version>
     </dependency>
 		<dependency>
 			<groupId>org.slf4j</groupId>
 			<artifactId>jul-to-slf4j</artifactId>
-			<version>1.7.30</version>
+			<version>1.7.32</version>
 		</dependency>
 		
 		<dependency>
 		    <groupId>net.sf.ehcache</groupId>
 		    <artifactId>ehcache</artifactId>
-		    <version>2.10.5</version>
+		    <version>2.10.9.2</version>
 		</dependency>
 
 		<!-- SQLite for database connection tests -->
 		<dependency>
 			<groupId>org.xerial</groupId>
 			<artifactId>sqlite-jdbc</artifactId>
-			<version>3.7.2</version>
+			<version>3.36.0.1</version>
 		</dependency>
 
 		<!-- Database Connection Pool Manager -->
 		<dependency>
-			<groupId>c3p0</groupId>
+			<groupId>com.mchange</groupId>
 			<artifactId>c3p0</artifactId>
-			<version>0.9.1.2</version>
+			<version>0.9.5.5</version>
 		</dependency>
 
 		<!-- Lucene core dependency -->
@@ -133,7 +136,7 @@
 			<artifactId>lucene-core</artifactId>
 			<groupId>org.apache.lucene</groupId>
 			<type>jar</type>
-			<version>5.0.0</version>
+			<version>${lucene.version}</version>
 		</dependency>
 
 		<!-- Lucene queryparser dependency -->
@@ -141,7 +144,7 @@
 			<artifactId>lucene-queryparser</artifactId>
 			<groupId>org.apache.lucene</groupId>
 			<type>jar</type>
-			<version>5.0.0</version>
+			<version>${lucene.version}</version>
 		</dependency>
 
 		<!-- Lucene analyzers dependency -->
@@ -149,20 +152,14 @@
 			<artifactId>lucene-analyzers-common</artifactId>
 			<groupId>org.apache.lucene</groupId>
 			<type>jar</type>
-			<version>5.0.0</version>
-		</dependency>
-
-		<dependency>
-			<groupId>org.hamcrest</groupId>
-			<artifactId>hamcrest-core</artifactId>
-			<version>1.3</version>
+			<version>${lucene.version}</version>
 		</dependency>
 
 		<!-- JCache -->
 		<dependency>
 			<groupId>net.sf.jsr107cache</groupId>
 			<artifactId>jsr107cache</artifactId>
-			<version>1.0</version>
+			<version>1.1</version>
 		</dependency>
 
 		<!-- Jersey -->
@@ -178,6 +175,12 @@
 			<version>${jackson.version}</version>
 		</dependency>
 
+                <dependency>
+                  <groupId>org.glassfish.jersey.inject</groupId>
+                  <artifactId>jersey-hk2</artifactId>
+                  <version>${jersey.version}</version>
+                </dependency>
+
 		<!-- JSON support using Jackson -->
 		<!-- see https://github.com/FasterXML/jackson-core -->
 		<!-- https://github.com/FasterXML/jackson-databind -->
@@ -217,14 +220,14 @@
     	<dependency>
 		    <groupId>commons-io</groupId>
 		    <artifactId>commons-io</artifactId>
-		    <version>2.7</version>
+		    <version>2.11.0</version>
 		</dependency>
 
     <!-- https://mvnrepository.com/artifact/org.codehaus.mojo/cobertura-maven-plugin -->
     <dependency>
       <groupId>org.codehaus.mojo</groupId>
       <artifactId>cobertura-maven-plugin</artifactId>
-      <version>2.7</version>
+      <version>${cobertura.version}</version>
       <scope>test</scope>
     </dependency>
   </dependencies>
@@ -247,7 +250,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-shade-plugin</artifactId>
-				<version>3.2.1</version>
+				<version>3.2.4</version>
 				<executions>
 					<execution>
 						<id>indexer</id>
@@ -322,7 +325,7 @@
 			<plugin>
 				<groupId>org.codehaus.mojo</groupId>
 				<artifactId>exec-maven-plugin</artifactId>
-				<version>1.6.0</version>
+				<version>3.0.0</version>
 				<executions>
 					<execution>
 						<goals>
@@ -338,7 +341,7 @@
 			<plugin>
 				<groupId>org.codehaus.mojo</groupId>
 				<artifactId>cobertura-maven-plugin</artifactId>
-				<version>2.7</version>
+				<version>${cobertura.version}</version>
 				<configuration>
 					<formats>
 						<format>html</format>
diff --git a/src/test/java/de/ids_mannheim/korap/server/TestDatabase.java b/src/test/java/de/ids_mannheim/korap/server/TestDatabase.java
index a096c47..2b871de 100644
--- a/src/test/java/de/ids_mannheim/korap/server/TestDatabase.java
+++ b/src/test/java/de/ids_mannheim/korap/server/TestDatabase.java
@@ -196,8 +196,6 @@
         assertEquals(rs.getInt("text_id"), 94);
         assertEquals(rs.getInt("match_count"), 456);
         assertFalse(rs.next());
-
-        stat.close();
     };