diff --git a/src/avian/constants.h b/src/avian/constants.h
index ef2bc24364..ebeb975af3 100644
--- a/src/avian/constants.h
+++ b/src/avian/constants.h
@@ -258,6 +258,7 @@ const unsigned ACC_SUPER = 1 << 5;
 const unsigned ACC_SYNCHRONIZED = ACC_SUPER;
 const unsigned ACC_VOLATILE = 1 << 6;
 const unsigned ACC_TRANSIENT = 1 << 7;
+const unsigned ACC_VARARGS = 1 << 7;
 const unsigned ACC_NATIVE = 1 << 8;
 const unsigned ACC_INTERFACE = 1 << 9;
 const unsigned ACC_ABSTRACT = 1 << 10;
diff --git a/src/avian/machine.h b/src/avian/machine.h
index 3011dd47ed..d1fa2cced9 100644
--- a/src/avian/machine.h
+++ b/src/avian/machine.h
@@ -125,10 +125,15 @@ using namespace avian::util;
     type2 name2;                                                     \
   } MAKE_NAME(resource_)(t, name1, name2);
 
+AVIAN_EXPORT void vmPrintTrace(vm::Thread* t);
+
+AVIAN_EXPORT void vmfPrintTrace(vm::Thread* t, FILE* out);
+
 namespace vm {
 
 const bool Verbose = false;
 const bool DebugRun = false;
+const bool DebugCalls = false;
 const bool DebugStack = false;
 const bool DebugMonitors = false;
 const bool DebugReferences = false;
@@ -2559,10 +2564,6 @@ void popResources(Thread* t);
 
 }  // namespace vm
 
-AVIAN_EXPORT void vmPrintTrace(vm::Thread* t);
-
-AVIAN_EXPORT void vmfPrintTrace(vm::Thread* t, FILE* out);
-
 namespace vm {
 
 void dumpHeap(Thread* t, FILE* out);
diff --git a/src/classpath-openjdk.cpp b/src/classpath-openjdk.cpp
index 5d4ef7ce51..dfc8464c2e 100644
--- a/src/classpath-openjdk.cpp
+++ b/src/classpath-openjdk.cpp
@@ -4880,9 +4880,8 @@ uint64_t jvmGetClassDeclaredConstructors(Thread* t, uintptr_t* arguments)
       GcMethod* vmMethod = cast<GcMethod>(t, table->body()[i]);
       PROTECT(t, vmMethod);
 
-      if (((not publicOnly) or (vmMethod->flags() & ACC_PUBLIC))
-          and strcmp(reinterpret_cast<char*>(vmMethod->name()->body().begin()),
-                     "<init>") == 0) {
+      bool isCtor = strcmp(reinterpret_cast<char*>(vmMethod->name()->body().begin()), "<init>") == 0;
+      if (((not publicOnly) or (vmMethod->flags() & ACC_PUBLIC)) and isCtor) {
         object method = makeJconstructor(t, vmMethod, i);
 
         assertT(t, ai < objectArrayLength(t, array));
diff --git a/src/interpret.cpp b/src/interpret.cpp
index 6ed8fefe03..12ddc9e0bb 100644
--- a/src/interpret.cpp
+++ b/src/interpret.cpp
@@ -574,10 +574,11 @@ unsigned invokeNativeSlow(Thread* t, GcMethod* method, void* function)
   uint64_t result;
 
   if (DebugRun) {
+    signed char *cname = method->class_() && method->class_()->name() ? method->class_()->name()->body().begin() : (signed char*) "?";
+    signed char *mname = method->name() ? method->name()->body().begin() : (signed char*) "?";
     fprintf(stderr,
             "invoke native method %s.%s\n",
-            method->class_()->name()->body().begin(),
-            method->name()->body().begin());
+            cname, mname);
   }
 
   {
@@ -785,12 +786,13 @@ loop:
   instruction = code->body()[ip++];
 
   if (DebugRun) {
+    GcMethod *method_ = frameMethod(t, frame);
+    signed char *cname = method_->class_() && method_->class_()->name() ? method_->class_()->name()->body().begin() : (signed char*) "?";
+    signed char *mname = method_->name() ? method_->name()->body().begin() : (signed char*) "?";
     fprintf(stderr,
             "ip: %d; instruction: 0x%x in %s.%s ",
             ip - 1,
-            instruction,
-            frameMethod(t, frame)->class_()->name()->body().begin(),
-            frameMethod(t, frame)->name()->body().begin());
+            instruction, cname, mname);
 
     int line = findLineNumber(t, frameMethod(t, frame), ip);
     switch (line) {
@@ -2989,6 +2991,12 @@ invoke : {
   if (method->flags() & ACC_NATIVE) {
     invokeNative(t, method);
   } else {
+    if (DebugCalls && method) {
+      printf("invoke %s.%s\n", 
+                method->class_() && method->class_()->name() ? (const char *)method->class_()->name()->body().begin() : "<?>",
+                method->name() ? (const char *)method->name()->body().begin() : "<?>"
+      );
+    }
     checkStack(t, method);
     pushFrame(t, method);
   }
@@ -2996,8 +3004,8 @@ invoke : {
   goto loop;
 
 throw_:
-  if (DebugRun) {
-    fprintf(stderr, "throw\n");
+  if (DebugRun || DebugCalls) {
+    fprintf(stderr, "throw @ %s\n", frameMethod(t, frame)->name()->body().begin());
   }
 
   pokeInt(t, t->frame + FrameIpOffset, t->ip);