diff --git a/build.gradle b/build.gradle
index ae3ac7a..c4a27d6 100644
--- a/build.gradle
+++ b/build.gradle
@@ -47,7 +47,7 @@ dependencies {
     compile group: 'org.codehaus.groovy', name: 'groovy-all', version:'2.2.1'
 
     testCompile group: 'junit', name: 'junit', version:'4.13.2'
-    testCompile group: 'org.mockito', name: 'mockito-core', version:'1.9.5'
+    testCompile group: 'org.mockito', name: 'mockito-core', version:'4.2.0'
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
 }
 compileKotlin {