diff --git a/platform/platform-api/src/com/intellij/util/io/HttpRequests.java b/platform/platform-api/src/com/intellij/util/io/HttpRequests.java
index dd8624ce5c4f..acc1d8b53fd3 100644
--- a/platform/platform-api/src/com/intellij/util/io/HttpRequests.java
+++ b/platform/platform-api/src/com/intellij/util/io/HttpRequests.java
@@ -352,15 +352,15 @@ public final class HttpRequests {
   }
 
   private static <T> T process(RequestBuilderImpl builder, RequestProcessor<T> processor) throws IOException {
-    if (!UrlClassLoader.PARALLEL_CAPABLE) {
+    ClassLoader contextLoader = Thread.currentThread().getContextClassLoader();
+    if (!UrlClassLoader.isRegisteredAsParallelCapable(contextLoader)) {
       // hack-around for class loader lock in sun.net.www.protocol.http.NegotiateAuthentication (IDEA-131621)
-      ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
-      try (URLClassLoader cl = new URLClassLoader(new URL[0], oldClassLoader)) {
+      try (URLClassLoader cl = new URLClassLoader(new URL[0], contextLoader)) {
         Thread.currentThread().setContextClassLoader(cl);
         return doProcess(builder, processor);
       }
       finally {
-        Thread.currentThread().setContextClassLoader(oldClassLoader);
+        Thread.currentThread().setContextClassLoader(contextLoader);
       }
     }
     else {
diff --git a/platform/util/src/com/intellij/util/lang/UrlClassLoader.java b/platform/util/src/com/intellij/util/lang/UrlClassLoader.java
index cf81a2272034..82de631a11af 100644
--- a/platform/util/src/com/intellij/util/lang/UrlClassLoader.java
+++ b/platform/util/src/com/intellij/util/lang/UrlClassLoader.java
@@ -29,6 +29,7 @@ import org.jetbrains.annotations.Nullable;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.net.MalformedURLException;
 import java.net.URL;
@@ -45,20 +46,31 @@ import java.util.List;
 public class UrlClassLoader extends ClassLoader {
   public static final String CLASS_EXTENSION = ".class";
 
-  public static final boolean PARALLEL_CAPABLE;
+  private static final boolean HAS_PARALLEL_LOADERS = SystemInfo.isJavaVersionAtLeast("1.7") && !SystemInfo.isIbmJvm;
+
   static {
-    boolean parallelCapable = false;
-    if (SystemInfo.isJavaVersionAtLeast("1.7") && !SystemInfo.isIbmJvm) {
+    if (HAS_PARALLEL_LOADERS) {
       try {
-        // todo Patches.USE_REFLECTION_TO_ACCESS_JDK7
+        //todo Patches.USE_REFLECTION_TO_ACCESS_JDK7
         Method registerAsParallelCapable = ClassLoader.class.getDeclaredMethod("registerAsParallelCapable");
         registerAsParallelCapable.setAccessible(true);
         registerAsParallelCapable.invoke(null);
-        parallelCapable = true;
       }
       catch (Exception ignored) { }
     }
-    PARALLEL_CAPABLE = parallelCapable;
+  }
+
+  public static boolean isRegisteredAsParallelCapable(@NotNull ClassLoader loader) {
+    if (!HAS_PARALLEL_LOADERS) return false;
+    try {
+      //todo Patches.USE_REFLECTION_TO_ACCESS_JDK7
+      Field parallelLockMap = ClassLoader.class.getDeclaredField("parallelLockMap");
+      parallelLockMap.setAccessible(true);
+      return parallelLockMap.get(loader) != null;
+    }
+    catch (Exception e) {
+      throw new AssertionError("Internal error: ClassLoader implementation has been altered");
+    }
   }
 
   private static final boolean ourClassPathIndexEnabled = Boolean.parseBoolean(System.getProperty("idea.classpath.index.enabled", "true"));
@@ -161,7 +173,7 @@ public class UrlClassLoader extends ClassLoader {
     });
     myClassPath = createClassPath(builder);
     myAllowBootstrapResources = builder.myAllowBootstrapResources;
-    myClassNameInterner = PARALLEL_CAPABLE ? new WeakStringInterner() : null;
+    myClassNameInterner = isRegisteredAsParallelCapable(this) ? new WeakStringInterner() : null;
   }
 
   @NotNull
@@ -332,6 +344,8 @@ public class UrlClassLoader extends ClassLoader {
     else return "";
   }
 
+  // called by a parent class on Java 7+
+  @SuppressWarnings("unused")
   protected Object getClassLoadingLock(String className) {
     return myClassNameInterner != null ? myClassNameInterner.intern(new String(className)) : this;
   }