diff --git a/build.gradle b/build.gradle
index b934871..b196d87 100644
--- a/build.gradle
+++ b/build.gradle
@@ -10,13 +10,9 @@ repositories {
 }
 
 dependencies {
-    compile group: 'org.bouncycastle', name: 'bcmail-jdk15on', version: '1.54'
-    compile group: 'org.bouncycastle', name: 'bcprov-jdk15on', version: '1.54'
-    compile group: 'javax.mail', name: 'javax.mail-api', version: '1.5.4'
-    compile group: 'com.sun.mail', name: 'javax.mail', version: '1.5.4'
+    compile group: 'org.bouncycastle', name: 'bcmail-jdk15on', version: '1.62'
+    compile group: 'org.bouncycastle', name: 'bcprov-jdk15on', version: '1.62'
+    compile group: 'javax.mail', name: 'javax.mail-api', version: '1.6.2'
+    compile group: 'com.sun.mail', name: 'javax.mail', version: '1.6.2'
     testCompile group: 'junit', name: 'junit', version: '4.12'
 }
-
-task wrapper(type: Wrapper) {
-    gradleVersion = '2.13'
-}
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 8513fea..d75db5a 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.13-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-bin.zip