diff --git a/springloaded/src/main/java/org/springsource/loaded/GlobalConfiguration.java b/springloaded/src/main/java/org/springsource/loaded/GlobalConfiguration.java
index 13feab6..fcba3c1 100644
--- a/springloaded/src/main/java/org/springsource/loaded/GlobalConfiguration.java
+++ b/springloaded/src/main/java/org/springsource/loaded/GlobalConfiguration.java
@@ -86,6 +86,9 @@ public class GlobalConfiguration {
 	 * Determine whether on disk caching will be used.
 	 */
 	public static boolean isCaching = false;
+	
+	public static boolean investigateSystemClassReflection = false;
+	public static boolean rewriteAllSystemClasses = false;
 
 	/**
 	 * A well known profile (e.g. grails) can tweak a lot of the default options in a particular way.
@@ -286,6 +289,12 @@ public class GlobalConfiguration {
 							verboseMode = true;
 							reloadMessages = true;
 						}
+						else if (kv.equals("investigateSystemClassReflection")) {
+							investigateSystemClassReflection = true;
+						}
+						else if (kv.equals("rewriteAllSystemClasses")) {
+							rewriteAllSystemClasses = true;
+						}
 						else if (kv.equals("asserts")) {
 							Log.log("[asserts mode on] Will verify system coherence");
 							assertsMode = true;
diff --git a/springloaded/src/main/java/org/springsource/loaded/SystemClassReflectionInvestigator.java b/springloaded/src/main/java/org/springsource/loaded/SystemClassReflectionInvestigator.java
index c4be72b..1397154 100644
--- a/springloaded/src/main/java/org/springsource/loaded/SystemClassReflectionInvestigator.java
+++ b/springloaded/src/main/java/org/springsource/loaded/SystemClassReflectionInvestigator.java
@@ -31,9 +31,10 @@ import org.objectweb.asm.Opcodes;
  */
 public class SystemClassReflectionInvestigator {
 
-	public static int investigate(String slashedClassName, byte[] bytes) {
+	
+	public static int investigate(String slashedClassName, byte[] bytes, boolean print) {
 		ClassReader fileReader = new ClassReader(bytes);
-		RewriteClassAdaptor classAdaptor = new RewriteClassAdaptor();
+		RewriteClassAdaptor classAdaptor = new RewriteClassAdaptor(print);
 		fileReader.accept(classAdaptor, ClassReader.SKIP_FRAMES);
 		return classAdaptor.hitCount;
 	}
@@ -43,15 +44,17 @@ public class SystemClassReflectionInvestigator {
 		int hitCount = 0;
 		private ClassWriter cw;
 		int bits = 0x0000;
+		private boolean print;
 		private String classname;
 
 		private static boolean isInterceptable(String owner, String methodName) {
 			return MethodInvokerRewriter.RewriteClassAdaptor.intercepted.contains(owner + "." + methodName);
 		}
 
-		public RewriteClassAdaptor() {
+		public RewriteClassAdaptor(boolean print) {
 			// TODO should it also compute frames?
 			super(ASM5,new ClassWriter(ClassWriter.COMPUTE_MAXS));
+			this.print = print;
 			cw = (ClassWriter) cv;
 		}
 
@@ -85,7 +88,9 @@ public class SystemClassReflectionInvestigator {
 			private boolean interceptReflection(String owner, String name, String desc) {
 				if (isInterceptable(owner, name)) {
 					hitCount++;
-					System.out.println("SystemClassReflectionInvestigator: " + classname + "  uses " + owner + "." + name + desc);
+					if (print) {
+						System.out.println("SystemClassReflectionInvestigator: " + classname + "  uses " + owner + "." + name + desc);
+					}
 				}
 				return false;
 			}
diff --git a/springloaded/src/main/java/org/springsource/loaded/agent/SpringLoadedPreProcessor.java b/springloaded/src/main/java/org/springsource/loaded/agent/SpringLoadedPreProcessor.java
index 2f64011..46fc820 100644
--- a/springloaded/src/main/java/org/springsource/loaded/agent/SpringLoadedPreProcessor.java
+++ b/springloaded/src/main/java/org/springsource/loaded/agent/SpringLoadedPreProcessor.java
@@ -36,6 +36,7 @@ import org.springsource.loaded.LoadtimeInstrumentationPlugin;
 import org.springsource.loaded.Log;
 import org.springsource.loaded.Plugin;
 import org.springsource.loaded.ReloadableType;
+import org.springsource.loaded.SystemClassReflectionInvestigator;
 import org.springsource.loaded.SystemClassReflectionRewriter;
 import org.springsource.loaded.TypeRegistry;
 import org.springsource.loaded.Utils;
@@ -147,21 +148,25 @@ public class SpringLoadedPreProcessor implements Constants {
 					} catch (Exception re) {
 						re.printStackTrace();
 					}
-					// This block can help when you suspect there is a system class using reflection and that
-					// class isn't on the 'shortlist' (in systemClassesContainingReflection). Currently we skip
-					// this for performance, we could make it optional baed on a configuration option
-					//	} else {
-					//		// We should really track whether this type is using reflection...
-					//		if (SystemClassReflectionInvestigator.investigate(slashedClassName, bytes) > 0) {
-					//		RewriteResult rr = SystemClassReflectionRewriter.rewrite(slashedClassName, bytes);
-					//		System.err.println("Type " + slashedClassName + " rewrite summary: " + rr.summarize());
-					//		systemClassesRequiringInitialization.put(slashedClassName, rr.bits);
-					//		return rr.bytes;
-					//	}
+					
 				}
 				else if (slashedClassName.equals("java/lang/invoke/InnerClassLambdaMetafactory")) {
 					bytes = Java8.enhanceInnerClassLambdaMetaFactory(bytes);
 					return bytes;
+				} else if ((GlobalConfiguration.investigateSystemClassReflection || GlobalConfiguration.rewriteAllSystemClasses) && 
+						SystemClassReflectionInvestigator.investigate(slashedClassName, bytes, GlobalConfiguration.investigateSystemClassReflection) > 0) {
+					// This block can help when you suspect there is a system class using reflection and that
+					// class isn't on the 'shortlist' (in systemClassesContainingReflection). Basically turn on the 
+					// options to trigger this investigation then add them to the shortlist if it looks like they need rewriting.
+					RewriteResult rr = SystemClassReflectionRewriter.rewrite(slashedClassName, bytes);
+					if (GlobalConfiguration.rewriteAllSystemClasses) {
+						systemClassesRequiringInitialization.put(slashedClassName, rr.bits);
+						return rr.bytes;
+					}
+					else {
+						System.err.println("Type " + slashedClassName + " rewrite summary: " + rr.summarize());
+						return bytes;
+					}
 				}
 			}
 			return bytes;