diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 1c7c90c..7a3265e 100644
--- a/gradle/wrapper/gradle-wrapper.jar
+++ b/gradle/wrapper/gradle-wrapper.jar
Binary files differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 117efd1..f16d266 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,5 @@
-#Tue Apr 25 07:35:34 CEST 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-bin.zip
diff --git a/gradlew b/gradlew
index 4453cce..cccdd3d 100755
--- a/gradlew
+++ b/gradlew
@@ -33,11 +33,11 @@
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
 
-warn ( ) {
+warn () {
     echo "$*"
 }
 
-die ( ) {
+die () {
     echo
     echo "$*"
     echo
@@ -155,7 +155,7 @@
 fi
 
 # Escape application args
-save ( ) {
+save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }
diff --git a/tests/build.gradle b/tests/build.gradle
index 979a2f8..1f94b14 100644
--- a/tests/build.gradle
+++ b/tests/build.gradle
@@ -61,7 +61,7 @@
     scalaCompileOptions.additionalParameters = gradle.scala.compileFlags
 }
 
-def keystorePath = new File(buildDir, 'classes/test/keystore')
+def keystorePath = new File(sourceSets.test.scala.outputDir, 'keystore')
 task deleteKeystore(type: Delete) {
     delete keystorePath
 }