diff --git a/plugin/build.gradle b/plugin/build.gradle
index c661a9d6fc2..7b624864ad0 100644
--- a/plugin/build.gradle
+++ b/plugin/build.gradle
@@ -224,7 +224,7 @@ task createNodeKeyStore(type: LoggedExec) {
       delete nodeKeystore
     }
   }
-  executable = new File(project.javaHome, 'bin/keytool')
+  executable = new File(project.runtimeJavaHome, 'bin/keytool')
   standardInput = new ByteArrayInputStream('FirstName LastName\nUnit\nOrganization\nCity\nState\nNL\nyes\n\n'.getBytes('UTF-8'))
   args '-genkey',
           '-alias', 'test-node',
diff --git a/plugin/bwc-snapshot-dummy-projects/build.gradle b/plugin/bwc-snapshot-dummy-projects/build.gradle
index 04c8115e2a3..a4492f011f7 100644
--- a/plugin/bwc-snapshot-dummy-projects/build.gradle
+++ b/plugin/bwc-snapshot-dummy-projects/build.gradle
@@ -186,25 +186,31 @@ subprojects {
     task buildBwcVersion(type: Exec) {
       dependsOn checkoutXPackBwcBranch, checkoutElasticsearchBwcBranch, writeElasticsearchBuildMetadata, writeXPackBuildMetadata
       workingDir = xpackCheckoutDir
+      if (project.rootProject.ext.runtimeJavaVersion == JavaVersion.VERSION_1_8 && ["5.6", "6.0", "6.1"].contains(bwcBranch)) {
+        /*
+         * If runtime Java home is set to JDK 8 and we are building branches that are officially built with JDK 8, push this to JAVA_HOME for
+         * these builds.
+         */
+        environment('JAVA_HOME', System.getenv('RUNTIME_JAVA_HOME'))
+      }
       if (Os.isFamily(Os.FAMILY_WINDOWS)) {
         executable 'cmd'
         args '/C', 'call', new File(xpackCheckoutDir, 'gradlew').toString()
       } else {
-        executable = new File(xpackCheckoutDir, 'gradlew').toString()
+        executable new File(xpackCheckoutDir, 'gradlew').toString()
       }
-      final ArrayList<String> commandLineArgs = [":x-pack-elasticsearch:plugin:assemble", "-Dbuild.snapshot=${System.getProperty('build.snapshot') ?: 'true'}"]
+      args ":x-pack-elasticsearch:plugin:assemble", "-Dbuild.snapshot=${System.getProperty('build.snapshot') ?: 'true'}"
       final LogLevel logLevel = gradle.startParameter.logLevel
       if ([LogLevel.QUIET, LogLevel.WARN, LogLevel.INFO, LogLevel.DEBUG].contains(logLevel)) {
-        commandLineArgs << "--${logLevel.name().toLowerCase(Locale.ENGLISH)}"
+        args "--${logLevel.name().toLowerCase(Locale.ENGLISH)}"
       }
       final String showStacktraceName = gradle.startParameter.showStacktrace.name()
       assert ["INTERNAL_EXCEPTIONS", "ALWAYS", "ALWAYS_FULL"].contains(showStacktraceName)
       if (showStacktraceName.equals("ALWAYS")) {
-        commandLineArgs << "--stacktrace"
+        args "--stacktrace"
       } else if (showStacktraceName.equals("ALWAYS_FULL")) {
-        commandLineArgs << "--full-stacktrace"
+        args "--full-stacktrace"
       }
-      args commandLineArgs
     }
 
     artifacts {
diff --git a/qa/smoke-test-plugins-ssl/build.gradle b/qa/smoke-test-plugins-ssl/build.gradle
index 2aef43a1774..75b089bd22c 100644
--- a/qa/smoke-test-plugins-ssl/build.gradle
+++ b/qa/smoke-test-plugins-ssl/build.gradle
@@ -42,7 +42,7 @@ task createNodeKeyStore(type: LoggedExec) {
       delete nodeKeystore
     }
   }
-  executable = new File(project.javaHome, 'bin/keytool')
+  executable = new File(project.runtimeJavaHome, 'bin/keytool')
   standardInput = new ByteArrayInputStream('FirstName LastName\nUnit\nOrganization\nCity\nState\nNL\nyes\n\n'.getBytes('UTF-8'))
   args '-genkey',
           '-alias', 'test-node',
@@ -67,7 +67,7 @@ task createClientKeyStore(type: LoggedExec) {
       delete clientKeyStore
     }
   }
-  executable = new File(project.javaHome, 'bin/keytool')
+  executable = new File(project.runtimeJavaHome, 'bin/keytool')
   standardInput = new ByteArrayInputStream('FirstName LastName\nUnit\nOrganization\nCity\nState\nNL\nyes\n\n'.getBytes('UTF-8'))
   args '-genkey',
           '-alias', 'test-client',
@@ -92,7 +92,7 @@ task exportNodeCertificate(type: LoggedExec) {
       delete nodeCertificate
     }
   }
-  executable = new File(project.javaHome, 'bin/keytool')
+  executable = new File(project.runtimeJavaHome, 'bin/keytool')
   args '-export',
           '-alias', 'test-node',
           '-keystore', nodeKeystore,
@@ -103,7 +103,7 @@ task exportNodeCertificate(type: LoggedExec) {
 // Import the node certificate in the client's keystore
 task importNodeCertificateInClientKeyStore(type: LoggedExec) {
   dependsOn exportNodeCertificate
-  executable = new File(project.javaHome, 'bin/keytool')
+  executable = new File(project.runtimeJavaHome, 'bin/keytool')
   args '-import',
           '-alias', 'test-node',
           '-keystore', clientKeyStore,
@@ -123,7 +123,7 @@ task exportClientCertificate(type: LoggedExec) {
       delete clientCertificate
     }
   }
-  executable = new File(project.javaHome, 'bin/keytool')
+  executable = new File(project.runtimeJavaHome, 'bin/keytool')
   args '-export',
           '-alias', 'test-client',
           '-keystore', clientKeyStore,
@@ -134,7 +134,7 @@ task exportClientCertificate(type: LoggedExec) {
 // Import the client certificate in the node's keystore
 task importClientCertificateInNodeKeyStore(type: LoggedExec) {
   dependsOn exportClientCertificate
-  executable = new File(project.javaHome, 'bin/keytool')
+  executable = new File(project.runtimeJavaHome, 'bin/keytool')
   args '-import',
           '-alias', 'test-client',
           '-keystore', nodeKeystore,