diff --git a/jOOR/src/main/java/org/joor/CompileUnit.java b/jOOR/src/main/java/org/joor/MultiCompile.java
similarity index 94%
rename from jOOR/src/main/java/org/joor/CompileUnit.java
rename to jOOR/src/main/java/org/joor/MultiCompile.java
index 746e0c6..2b09195 100644
--- a/jOOR/src/main/java/org/joor/CompileUnit.java
+++ b/jOOR/src/main/java/org/joor/MultiCompile.java
@@ -35,13 +35,11 @@
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.Deque;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.stream.Stream;
 
 import static java.lang.StackWalker.Option.RETAIN_CLASS_REFERENCE;
 
@@ -50,8 +48,15 @@
  *
  * @author Lukas Eder
  */
-public class CompileUnit {
-
+public class MultiCompile {
+
+    /**
+     * Compiles multiple files as one unit
+     *
+     * @param unit           the files to compile in the same unit
+     * @param compileOptions compile options
+     * @return the compilation result
+     */
     public static CompilationUnit.Result compileUnit(CompilationUnit unit, CompileOptions compileOptions) {
         CompilationUnit.Result result = CompilationUnit.result();
 
@@ -130,24 +135,15 @@ public static CompilationUnit.Result compileUnit(CompilationUnit unit, CompileOp
                 // This method is called by client code from two levels up the current stack frame
                 // We need a private-access lookup from the class in that stack frame in order to get
                 // private-access to any local interfaces at that location.
-//                Class<?> caller = StackWalker
-//                        .getInstance(RETAIN_CLASS_REFERENCE)
-//                        .walk(s -> s
-//                                .skip(2)
-//                                .findFirst()
-//                                .get()
-//                                .getDeclaringClass());
-
                 int index = 2;
                 for (CharSequenceJavaFileObject f : files) {
                     String className = f.getClassName();
 
-                    Class<?> caller = getClassFromIndex(index);
-                    index++;
+                    Class<?> caller = getClassFromIndex(index++);
 
                     // If the compiled class is in the same package as the caller class, then
                     // we can use the private-access Lookup of the caller class
-                    if (className.startsWith(caller.getPackageName() + ".") &&
+                    if (caller != null && className.startsWith(caller.getPackageName() + ".") &&
 
                             // [#74] This heuristic is necessary to prevent classes in subpackages of the caller to be loaded
                             //       this way, as subpackages cannot access private content in super packages.
@@ -185,13 +181,13 @@ public static CompilationUnit.Result compileUnit(CompilationUnit unit, CompileOp
     }
 
     private static Class<?> getClassFromIndex(int index) {
-        return StackWalker
+        StackWalker.StackFrame sf = StackWalker
                 .getInstance(RETAIN_CLASS_REFERENCE)
                 .walk(s -> s
                         .skip(index)
                         .findFirst()
-                        .get()
-                        .getDeclaringClass());
+                        .orElse(null));
+        return sf != null ? sf.getDeclaringClass() : null;
     }
 
     /* [java-9] */
diff --git a/jOOR/src/main/java/org/joor/Reflect.java b/jOOR/src/main/java/org/joor/Reflect.java
index 8aa9713..1da139a 100644
--- a/jOOR/src/main/java/org/joor/Reflect.java
+++ b/jOOR/src/main/java/org/joor/Reflect.java
@@ -25,7 +25,6 @@
 import java.lang.reflect.Proxy;
 import java.util.Arrays;
 import java.util.LinkedHashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
@@ -52,7 +51,7 @@
 public class Reflect {
 
     public static CompilationUnit.Result compileUnit(CompilationUnit unit) throws ReflectException {
-        return CompileUnit.compileUnit(unit, new CompileOptions());
+        return MultiCompile.compileUnit(unit, new CompileOptions());
     }
 
     // ---------------------------------------------------------------------
diff --git a/jOOR/src/test/java/org/joor/test/CompileUnitTest.java b/jOOR/src/test/java/org/joor/test/MultiCompileTest.java
similarity index 68%
rename from jOOR/src/test/java/org/joor/test/CompileUnitTest.java
rename to jOOR/src/test/java/org/joor/test/MultiCompileTest.java
index 8d95c57..d0feacc 100644
--- a/jOOR/src/test/java/org/joor/test/CompileUnitTest.java
+++ b/jOOR/src/test/java/org/joor/test/MultiCompileTest.java
@@ -19,7 +19,7 @@
 
 import static org.junit.Assert.assertEquals;
 
-public class CompileUnitTest {
+public class MultiCompileTest {
 
     @Test
     public void testSingleUnit() throws Exception {
@@ -72,4 +72,38 @@ public void testDualUnit() throws Exception {
         assertEquals("Hi World!", out3);
     }
 
+    @Test
+    public void testClassLoadingOrder() throws Exception {
+        CompilationUnit unit = CompilationUnit.input()
+                .addClass("pm.A", "package pm; public class A extends B {}")
+                .addClass("pm.B", "package pm; public class B {}"
+                );
+
+        CompilationUnit.Result result = Reflect.compileUnit(unit);
+        assertEquals(2, result.size());
+
+        Class<?> a = Reflect.onClass(result.getClass("pm.A")).type();
+        Class<?> b = Reflect.onClass(result.getClass("pm.B")).type();
+        assertEquals("pm.A", a.getName());
+        assertEquals("pm.B", a.getSuperclass().getName());
+        assertEquals("pm.B", b.getName());
+    }
+
+    @Test
+    public void testClassLoadingOrderReverse() throws Exception {
+        CompilationUnit unit = CompilationUnit.input()
+                .addClass("pm.C", "package pm; public class C {}")
+                .addClass("pm.D", "package pm; public class D extends C {}"
+                );
+
+        CompilationUnit.Result result = Reflect.compileUnit(unit);
+        assertEquals(2, result.size());
+
+        Class<?> c = Reflect.onClass(result.getClass("pm.C")).type();
+        Class<?> d = Reflect.onClass(result.getClass("pm.D")).type();
+        assertEquals("pm.C", c.getName());
+        assertEquals("pm.D", d.getName());
+        assertEquals("pm.C", d.getSuperclass().getName());
+    }
+
 }