diff --git a/src/main/java/net/md_5/specialsource/JarInheritanceProvider.java b/src/main/java/net/md_5/specialsource/JarInheritanceProvider.java
index a30f370..d249d28 100644
--- a/src/main/java/net/md_5/specialsource/JarInheritanceProvider.java
+++ b/src/main/java/net/md_5/specialsource/JarInheritanceProvider.java
@@ -5,6 +5,9 @@ import org.objectweb.asm.tree.ClassNode;
 import java.util.ArrayList;
 import java.util.List;
 
+/**
+ * Lookup inheritance from a class given a jar
+ */
 public class JarInheritanceProvider implements IInheritanceProvider {
     private final Jar self;
 
@@ -14,14 +17,23 @@ public class JarInheritanceProvider implements IInheritanceProvider {
 
     @SuppressWarnings("unchecked") // Saddens me to see ASM strip vital info like that
     public List<String> getParents(String owner) {
+        System.out.println("jar: owner "+owner);
         List<String> parents = new ArrayList<String>();
         ClassNode node = self.getNode(owner);
         if (node != null) {
             for (String iface : (List<String>) node.interfaces) {
+                System.out.println("jar: add iface="+iface);
                 parents.add(iface);
             }
+            System.out.println("jar: add super="+node.superName);
             parents.add(node.superName);
+        } else {
+            System.out.println("jar: nothing for "+owner);
         }
         return parents;
     }
+
+    public String toString() {
+        return getClass().getSimpleName()+"("+self.file.getName()+")";
+    }
 }
diff --git a/src/main/java/net/md_5/specialsource/JarRemapper.java b/src/main/java/net/md_5/specialsource/JarRemapper.java
index f44cacc..ab48cd4 100644
--- a/src/main/java/net/md_5/specialsource/JarRemapper.java
+++ b/src/main/java/net/md_5/specialsource/JarRemapper.java
@@ -33,6 +33,7 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.List;
 import java.util.Map;
@@ -47,12 +48,12 @@ import org.objectweb.asm.tree.ClassNode;
 public class JarRemapper extends Remapper {
 
     private static final int CLASS_LEN = ".class".length();
-    private final IInheritanceProvider inheritanceProvider;
+    private final List<IInheritanceProvider> inheritanceProviders;
     private final JarMapping jarMapping;
 
-    private JarRemapper(JarMapping jarMapping, IInheritanceProvider inheritanceProvider) throws IOException {
+    private JarRemapper(JarMapping jarMapping, List<IInheritanceProvider> inheritanceProviders) throws IOException {
         this.jarMapping = jarMapping;
-        this.inheritanceProvider = inheritanceProvider;
+        this.inheritanceProviders = inheritanceProviders;
     }
 
     @Override
@@ -96,10 +97,12 @@ public class JarRemapper extends Remapper {
 
         String mapped = map.get(key);
         if (mapped == null) {
-            for (String parent : inheritanceProvider.getParents(owner)) {
-                mapped = tryClimb(map, type, parent, name);
-                if (mapped != null) {
-                    return mapped;
+            for (IInheritanceProvider inheritanceProvider : inheritanceProviders) {
+                for (String parent : inheritanceProvider.getParents(owner)) {
+                    mapped = tryClimb(map, type, parent, name);
+                    if (mapped != null) {
+                        return mapped;
+                    }
                 }
             }
         }
@@ -112,11 +115,15 @@ public class JarRemapper extends Remapper {
         return mapped == null ? name : mapped;
     }
 
-    public static void renameJar(Jar jar, File target, JarMapping jarMapping) throws IOException {
+    public static void renameJar(Jar jar, File target, JarMapping jarMapping, boolean live) throws IOException {
         JarOutputStream out = new JarOutputStream(new FileOutputStream(target));
         try {
-            JarInheritanceProvider jarInheritanceProvider = new JarInheritanceProvider(jar);
-            JarRemapper self = new JarRemapper(jarMapping, jarInheritanceProvider);
+            List<IInheritanceProvider> inheritanceProviders = new ArrayList<IInheritanceProvider>();
+            inheritanceProviders.add(new JarInheritanceProvider(jar));
+            if (live) {
+                inheritanceProviders.add(new RuntimeInheritanceProvider());
+            }
+            JarRemapper self = new JarRemapper(jarMapping, inheritanceProviders);
             if (jar == null) {
                 return;
             }
diff --git a/src/main/java/net/md_5/specialsource/RuntimeInheritanceProvider.java b/src/main/java/net/md_5/specialsource/RuntimeInheritanceProvider.java
new file mode 100644
index 0000000..521cad7
--- /dev/null
+++ b/src/main/java/net/md_5/specialsource/RuntimeInheritanceProvider.java
@@ -0,0 +1,49 @@
+package net.md_5.specialsource;
+
+import java.util.List;
+import java.util.ArrayList;
+
+/**
+ * Lookup class inheritance from classes loaded at runtime
+ */
+public class RuntimeInheritanceProvider implements IInheritanceProvider {
+    // TODO: option to transform through a jarRemapper at runtime
+
+    public List<String> getParents(String internalClassName) {
+        List<String> parents = new ArrayList<String>();
+        String sourceClassName = toSourceName(internalClassName);
+        Class clazz;
+        try {
+            clazz = ClassLoader.getSystemClassLoader().loadClass(sourceClassName); // load class without initializing
+            //clazz = Class.forName(toSourceName(sourceClassName)); // runs static initializers - avoid!
+        } catch (Throwable t) {
+            System.out.println("RuntimeInheritanceProvider failed: "+t);
+            return parents;
+        }
+
+        for (Class iface : clazz.getInterfaces()) {
+            parents.add(toInternalName(iface.getName()));
+        }
+
+        Class superClass = clazz.getSuperclass();
+        if (superClass != null) {
+            parents.add(toInternalName(superClass.getName()));
+        }
+
+        return parents;
+    }
+
+    // Convert class name from internal name to source name
+    public String toSourceName(String className) {
+        return className.replace('/', '.');
+    }
+
+    //  .. and vice versa
+    public String toInternalName(String className) {
+        return className.replace('.', '/');
+    }
+
+    public String toString() {
+        return this.getClass().getSimpleName();
+    }
+}
diff --git a/src/main/java/net/md_5/specialsource/SpecialSource.java b/src/main/java/net/md_5/specialsource/SpecialSource.java
index 3923c00..0edc33a 100644
--- a/src/main/java/net/md_5/specialsource/SpecialSource.java
+++ b/src/main/java/net/md_5/specialsource/SpecialSource.java
@@ -76,6 +76,8 @@ public class SpecialSource {
                         .withRequiredArg()
                         .withValuesSeparatedBy(',');
 
+                acceptsAll(asList("l", "live"), "Enable runtime inheritance lookup");
+
                 acceptsAll(asList("q", "quiet"), "Quiet mode");
                 acceptsAll(asList("c", "compact"), "Output mapping file in compact format");
             }
@@ -150,7 +152,7 @@ public class SpecialSource {
 
             log("Remapping final jar");
             Jar jar3 = Jar.init((File)options.valueOf("in-jar"));
-            JarRemapper.renameJar(jar3, (File)options.valueOf("out-jar"), jarMapping);
+            JarRemapper.renameJar(jar3, (File)options.valueOf("out-jar"), jarMapping, options.has("live"));
         }
     }