diff --git a/pom.xml b/pom.xml
index dc1b282..acc909c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -102,21 +102,21 @@
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
-            <version>${lombok.version}</version>
+            <version>1.18.10</version>
         </dependency>
 
         <!-- nullable-nonnull annotations -->
         <dependency>
             <groupId>com.google.code.findbugs</groupId>
             <artifactId>jsr305</artifactId>
-            <version>${jsr305.version}</version>
+            <version>3.0.2</version>
         </dependency>
 
         <!-- Cache -->
         <dependency>
             <groupId>org.cache2k</groupId>
             <artifactId>cache2k-base-bom</artifactId>
-            <version>${cache2k.version}</version>
+            <version>1.2.4.Final</version>
             <type>pom</type>
         </dependency>
 
@@ -124,71 +124,71 @@
         <dependency>
             <groupId>javax.persistence</groupId>
             <artifactId>javax.persistence-api</artifactId>
-            <version>${javax.persistence-api.version}</version>
+            <version>2.2</version>
         </dependency>
 
         <!-- for KryoSerializer -->
         <dependency>
             <groupId>com.esotericsoftware</groupId>
             <artifactId>kryo</artifactId>
-            <version>${kryo.version}</version>
+            <version>5.0.0-RC4</version>
         </dependency>
 
         <!-- for JacksonSerializer -->
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-core</artifactId>
-            <version>${jackson.version}</version>
+            <version>2.11.0</version>
         </dependency>
 
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
-            <version>${jackson.databind.version}</version>
+            <version>2.11.0</version>
         </dependency>
 
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>
             <artifactId>jackson-datatype-jsr310</artifactId>
-            <version>${jackson.version}</version>
+            <version>2.11.0</version>
         </dependency>
 
         <!-- for XStreamSerializer -->
         <dependency>
             <groupId>com.thoughtworks.xstream</groupId>
             <artifactId>xstream</artifactId>
-            <version>${xstream.version}</version>
+            <version>1.4.15</version>
         </dependency>
 
         <dependency>
             <groupId>xmlpull</groupId>
             <artifactId>xmlpull</artifactId>
-            <version>${xmlpull.version}</version>
+            <version>1.1.3.1</version>
         </dependency>
 
         <dependency>
             <groupId>org.ogce</groupId>
             <artifactId>xpp3</artifactId>
-            <version>${xpp3.version}</version>
+            <version>1.1.6</version>
         </dependency>
 
         <dependency>
             <groupId>net.bytebuddy</groupId>
             <artifactId>byte-buddy</artifactId>
-            <version>${byte-buddy.version}</version>
+            <version>1.10.1</version>
         </dependency>
 
         <dependency>
             <groupId>com.fasterxml.uuid</groupId>
             <artifactId>java-uuid-generator</artifactId>
-            <version>${java-uuid-generator.version}</version>
+            <version>3.2.0</version>
         </dependency>
 
         <!-- for distributed locks/offset -->
         <dependency>
             <groupId>org.redisson</groupId>
             <artifactId>redisson</artifactId>
-            <version>${redisson.version}</version>
+            <version>3.11.3</version>
             <exclusions>
                 <exclusion>
                     <groupId>com.fasterxml.jackson.core</groupId>
@@ -209,20 +209,20 @@
         <dependency>
             <groupId>ch.qos.logback</groupId>
             <artifactId>logback-classic</artifactId>
-            <version>${logback.version}</version>
+            <version>2.11.0</version>
         </dependency>
 
         <dependency>
             <groupId>ch.qos.logback</groupId>
             <artifactId>logback-core</artifactId>
-            <version>${logback.version}</version>
+            <version>1.2.3</version>
         </dependency>
 
         <!-- some reflection magic -->
         <dependency>
             <groupId>org.reflections</groupId>
             <artifactId>reflections</artifactId>
-            <version>${reflections.version}</version>
+            <version>0.9.12</version>
         </dependency>
 
         <!-- test dependencies -->
@@ -231,7 +231,7 @@
         <dependency>
             <groupId>org.postgresql</groupId>
             <artifactId>postgresql</artifactId>
-            <version>${postgresql.version}</version>
+            <version>42.3.9</version>
             <scope>test</scope>
             <exclusions>
                 <exclusion>
@@ -244,14 +244,14 @@
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
-            <version>${h2.version}</version>
+            <version>1.4.199</version>
             <scope>test</scope>
         </dependency>
 
         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
-            <version>${mysql.version}</version>
+            <version>8.0.20</version>
             <scope>test</scope>
         </dependency>
 
@@ -265,21 +265,21 @@
         <dependency>
             <groupId>com.zaxxer</groupId>
             <artifactId>HikariCP</artifactId>
-            <version>${HikariCP.version}</version>
+            <version>3.4.0</version>
             <scope>test</scope>
         </dependency>
 
         <dependency>
             <groupId>org.hibernate</groupId>
             <artifactId>hibernate-core</artifactId>
-            <version>${hibernate.version}</version>
+            <version>5.4.1.Final</version>
             <scope>test</scope>
         </dependency>
 
         <dependency>
             <groupId>org.testcontainers</groupId>
             <artifactId>testcontainers</artifactId>
-            <version>${testcontainers.version}</version>
+            <version>1.14.1</version>
             <exclusions>
                 <exclusion>
                     <groupId>org.jetbrains</groupId>
@@ -292,21 +292,21 @@
         <dependency>
             <groupId>org.testcontainers</groupId>
             <artifactId>postgresql</artifactId>
-            <version>${testcontainers.version}</version>
+            <version>1.14.1</version>
             <scope>test</scope>
         </dependency>
 
         <dependency>
             <groupId>org.testcontainers</groupId>
             <artifactId>mysql</artifactId>
-            <version>${testcontainers.version}</version>
+            <version>1.14.1</version>
             <scope>test</scope>
         </dependency>
 
         <dependency>
             <groupId>org.testcontainers</groupId>
             <artifactId>oracle-xe</artifactId>
-            <version>${testcontainers.version}</version>
+            <version>1.14.1</version>
             <scope>test</scope>
         </dependency>
 
@@ -321,21 +321,21 @@
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-api</artifactId>
-            <version>${junit-jupiter.version}</version>
+            <version>5.6.2</version>
             <scope>test</scope>
         </dependency>
 
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-params</artifactId>
-            <version>${junit-jupiter.version}</version>
+            <version>5.6.2</version>
             <scope>test</scope>
         </dependency>
 
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
-            <version>${junit-jupiter.version}</version>
+            <version>5.6.2</version>
             <scope>test</scope>
         </dependency>
 
@@ -349,14 +349,14 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${jmh.version}</version>
+            <version>1.21</version>
             <scope>test</scope>
         </dependency>
 
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh.version}</version>
+            <version>1.21</version>
             <scope>test</scope>
         </dependency>
     </dependencies>