Index: log4j-api/src/main/java/org/apache/logging/log4j/util/LoaderUtil.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- log4j-api/src/main/java/org/apache/logging/log4j/util/LoaderUtil.java	(revision 85576a653ad0caad75b246f6b09ed5f82acf622d)
+++ log4j-api/src/main/java/org/apache/logging/log4j/util/LoaderUtil.java	(revision )
@@ -52,6 +52,11 @@
 
     private static final PrivilegedAction<ClassLoader> TCCL_GETTER = new ThreadContextClassLoaderGetter();
 
+    private static final String PROPERTY_DISABLE_SYSTEM_CLASS_LOADER = "log4j2.disable.systemClassLoader";
+
+    private static final boolean USE_SYSTEM_CLASS_LOADER = !Boolean.parseBoolean(PropertiesUtil.getSystemProperties()
+            .getProperty(PROPERTY_DISABLE_SYSTEM_CLASS_LOADER));
+
     static {
         if (SECURITY_MANAGER != null) {
             boolean getClassLoaderDisabled;
@@ -94,7 +99,7 @@
                 return cl;
             }
             final ClassLoader ccl = LoaderUtil.class.getClassLoader();
-            return ccl == null ? ClassLoader.getSystemClassLoader() : ccl;
+            return ccl == null & USE_SYSTEM_CLASS_LOADER ? ClassLoader.getSystemClassLoader() : ccl;
         }
     }
 
@@ -192,7 +197,7 @@
         final ClassLoader[] candidates = {
             getThreadContextClassLoader(),
             LoaderUtil.class.getClassLoader(),
-            ClassLoader.getSystemClassLoader()
+            USE_SYSTEM_CLASS_LOADER ? ClassLoader.getSystemClassLoader() : null
         };
         final Collection<UrlResource> resources = new LinkedHashSet<>();
         for (final ClassLoader cl : candidates) {