diff --git a/fml/src/main/java/cpw/mods/fml/common/patcher/ClassPatchManager.java b/fml/src/main/java/cpw/mods/fml/common/patcher/ClassPatchManager.java
index 8df8d6d630..01243dce9e 100644
--- a/fml/src/main/java/cpw/mods/fml/common/patcher/ClassPatchManager.java
+++ b/fml/src/main/java/cpw/mods/fml/common/patcher/ClassPatchManager.java
@@ -38,6 +38,7 @@ public class ClassPatchManager {
     public static final ClassPatchManager INSTANCE = new ClassPatchManager();
 
     public static final boolean dumpPatched = Boolean.parseBoolean(System.getProperty("fml.dumpPatchedClasses", "false"));
+    public static final boolean DEBUG = Boolean.parseBoolean(System.getProperty("fml.debugClassPatchManager", "false"));
 
     private GDiffPatcher patcher = new GDiffPatcher();
     private ListMultimap<String, ClassPatch> patches;
@@ -75,7 +76,8 @@ public class ClassPatchManager {
             return inputData;
         }
         boolean ignoredError = false;
-        FMLRelaunchLog.fine("Runtime patching class %s (input size %d), found %d patch%s", mappedName, (inputData == null ? 0 : inputData.length), list.size(), list.size()!=1 ? "es" : "");
+        if (DEBUG)
+            FMLRelaunchLog.fine("Runtime patching class %s (input size %d), found %d patch%s", mappedName, (inputData == null ? 0 : inputData.length), list.size(), list.size()!=1 ? "es" : "");
         for (ClassPatch patch: list)
         {
             if (!patch.targetClassName.equals(mappedName) && !patch.sourceClassName.equals(name))
@@ -122,7 +124,7 @@ public class ClassPatchManager {
                 }
             }
         }
-        if (!ignoredError)
+        if (!ignoredError && DEBUG)
         {
             FMLRelaunchLog.fine("Successfully applied runtime patches for %s (new size %d)", mappedName, inputData.length);
         }
@@ -194,13 +196,15 @@ public class ClassPatchManager {
             }
         } while (true);
         FMLRelaunchLog.fine("Read %d binary patches", patches.size());
-        FMLRelaunchLog.fine("Patch list :\n\t%s", Joiner.on("\t\n").join(patches.asMap().entrySet()));
+        if (DEBUG)
+            FMLRelaunchLog.fine("Patch list :\n\t%s", Joiner.on("\t\n").join(patches.asMap().entrySet()));
         patchedClasses.clear();
     }
 
     private ClassPatch readPatch(JarEntry patchEntry, JarInputStream jis)
     {
-        FMLRelaunchLog.finer("Reading patch data from %s", patchEntry.getName());
+        if (DEBUG)
+            FMLRelaunchLog.finer("Reading patch data from %s", patchEntry.getName());
         ByteArrayDataInput input;
         try
         {