diff --git a/jps/jps-plugin/src/org/jetbrains/kotlin/compilerRunner/CompilerRunnerUtil.java b/jps/jps-plugin/src/org/jetbrains/kotlin/compilerRunner/CompilerRunnerUtil.java
index cc97d0376f3..6f93cb03680 100644
--- a/jps/jps-plugin/src/org/jetbrains/kotlin/compilerRunner/CompilerRunnerUtil.java
+++ b/jps/jps-plugin/src/org/jetbrains/kotlin/compilerRunner/CompilerRunnerUtil.java
@@ -70,7 +70,7 @@ public class CompilerRunnerUtil {
     }
 
     @Nullable
-    public synchronized static Object invokeExecMethod(
+    public static Object invokeExecMethod(
             @NotNull String compilerClassName,
             @NotNull String[] arguments,
             @NotNull CompilerEnvironment environment,
diff --git a/jps/jps-plugin/src/org/jetbrains/kotlin/compilerRunner/KotlinCompilerRunner.kt b/jps/jps-plugin/src/org/jetbrains/kotlin/compilerRunner/KotlinCompilerRunner.kt
index 71137f0051d..0463fd492db 100644
--- a/jps/jps-plugin/src/org/jetbrains/kotlin/compilerRunner/KotlinCompilerRunner.kt
+++ b/jps/jps-plugin/src/org/jetbrains/kotlin/compilerRunner/KotlinCompilerRunner.kt
@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.compilerRunner
 
 import com.intellij.util.xmlb.XmlSerializerUtil
+import org.jetbrains.jps.api.GlobalOptions
 import org.jetbrains.kotlin.cli.common.ExitCode
 import org.jetbrains.kotlin.cli.common.KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY
 import org.jetbrains.kotlin.cli.common.arguments.CommonCompilerArguments
@@ -117,9 +118,8 @@ public object KotlinCompilerRunner {
                 val stream = ByteArrayOutputStream()
                 val out = PrintStream(stream)
 
-// Uncomment after resolving problems with parallel compilation and tests
-//                if (System.getProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY) == null)
-//                    System.setProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY, "")
+                if (java.lang.Boolean.parseBoolean(System.getProperty(GlobalOptions.COMPILE_PARALLEL_OPTION, "false")))
+                    System.setProperty(KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY, "true")
 
                 val rc = CompilerRunnerUtil.invokeExecMethod(compilerClassName, argsArray, environment, messageCollector, out)
 
@@ -188,7 +188,7 @@ public object KotlinCompilerRunner {
             KotlinBuilder.LOG.debug("Try to connect to daemon")
             val connection = getDaemonConnection(environment, messageCollector)
 
-            if (connection?.daemon != null) {
+            if (connection.daemon != null) {
                 KotlinBuilder.LOG.info("Connected to daemon")
 
                 val compilerOut = ByteArrayOutputStream()
@@ -203,7 +203,7 @@ public object KotlinCompilerRunner {
                     K2JS_COMPILER -> CompileService.TargetPlatform.JS
                     else -> throw IllegalArgumentException("Unknown compiler type $compilerClassName")
                 }
-                val res = KotlinCompilerClient.incrementalCompile(connection!!.daemon!!, connection.sessionId, targetPlatform, argsArray, services, compilerOut, daemonOut)
+                val res = KotlinCompilerClient.incrementalCompile(connection.daemon!!, connection.sessionId, targetPlatform, argsArray, services, compilerOut, daemonOut)
 
                 processCompilerOutput(messageCollector, collector, compilerOut, res.toString())
                 BufferedReader(StringReader(daemonOut.toString())).forEachLine {