diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 1948b90..87b738c 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index d2c45a4..44e7c4d 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.8-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index cccdd3d..af6708f 100755
--- a/gradlew
+++ b/gradlew
@@ -28,7 +28,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
diff --git a/gradlew.bat b/gradlew.bat
index f955316..6d57edc 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -14,7 +14,7 @@ set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
+set DEFAULT_JVM_OPTS="-Xmx64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
diff --git a/samples/java/gradle/wrapper/gradle-wrapper.jar b/samples/java/gradle/wrapper/gradle-wrapper.jar
index 1948b90..87b738c 100644
Binary files a/samples/java/gradle/wrapper/gradle-wrapper.jar and b/samples/java/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/samples/java/gradle/wrapper/gradle-wrapper.properties b/samples/java/gradle/wrapper/gradle-wrapper.properties
index b61bef3..44e7c4d 100644
--- a/samples/java/gradle/wrapper/gradle-wrapper.properties
+++ b/samples/java/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,5 @@
-#Tue Jun 19 20:03:12 PDT 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.8-all.zip
diff --git a/samples/java/gradlew b/samples/java/gradlew
index cccdd3d..af6708f 100755
--- a/samples/java/gradlew
+++ b/samples/java/gradlew
@@ -28,7 +28,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
diff --git a/samples/java/gradlew.bat b/samples/java/gradlew.bat
index f955316..6d57edc 100644
--- a/samples/java/gradlew.bat
+++ b/samples/java/gradlew.bat
@@ -14,7 +14,7 @@ set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
+set DEFAULT_JVM_OPTS="-Xmx64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome
diff --git a/samples/kotlin/build.gradle.kts b/samples/kotlin/build.gradle.kts
index cbbf0ef..9f1f63b 100644
--- a/samples/kotlin/build.gradle.kts
+++ b/samples/kotlin/build.gradle.kts
@@ -1,6 +1,6 @@
 plugins {
     application
-    kotlin("jvm") version "1.2.50"
+    kotlin("jvm") version "1.3.0"
 }
 
 defaultTasks(ApplicationPlugin.TASK_RUN_NAME)
@@ -16,4 +16,4 @@ application {
 repositories {
     mavenLocal()
     jcenter()
-}
\ No newline at end of file
+}
diff --git a/samples/kotlin/gradle/wrapper/gradle-wrapper.jar b/samples/kotlin/gradle/wrapper/gradle-wrapper.jar
index 1948b90..87b738c 100644
Binary files a/samples/kotlin/gradle/wrapper/gradle-wrapper.jar and b/samples/kotlin/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/samples/kotlin/gradle/wrapper/gradle-wrapper.properties b/samples/kotlin/gradle/wrapper/gradle-wrapper.properties
index a4fc03d..44e7c4d 100644
--- a/samples/kotlin/gradle/wrapper/gradle-wrapper.properties
+++ b/samples/kotlin/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.8-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/samples/kotlin/gradlew b/samples/kotlin/gradlew
index cccdd3d..af6708f 100755
--- a/samples/kotlin/gradlew
+++ b/samples/kotlin/gradlew
@@ -28,7 +28,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
diff --git a/samples/kotlin/gradlew.bat b/samples/kotlin/gradlew.bat
index f955316..6d57edc 100644
--- a/samples/kotlin/gradlew.bat
+++ b/samples/kotlin/gradlew.bat
@@ -14,7 +14,7 @@ set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
+set DEFAULT_JVM_OPTS="-Xmx64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome