diff --git a/src/compile.cpp b/src/compile.cpp
index 22fc715c49..c95b4021ae 100644
--- a/src/compile.cpp
+++ b/src/compile.cpp
@@ -3875,11 +3875,11 @@ finish(MyThread* t, Context* context)
       strcmp
       (reinterpret_cast<const char*>
        (&byteArrayBody(t, className(t, methodClass(t, context->method)), 0)),
-       "java/lang/Number") == 0 and
+       "java/nio/ByteBuffer") == 0 and
       strcmp
       (reinterpret_cast<const char*>
        (&byteArrayBody(t, methodName(t, context->method), 0)),
-       "<init>") == 0)
+       "get") == 0)
   {
     asm("int3");
   }
diff --git a/src/compiler.cpp b/src/compiler.cpp
index 3c71af9c68..a06e8c93aa 100644
--- a/src/compiler.cpp
+++ b/src/compiler.cpp
@@ -355,7 +355,7 @@ bool
 tryAddSite(Context* c, Stack* stack, unsigned size, Value* v, Site* s)
 {
   if (not findSite(c, v, s)) {
-//     fprintf(stderr, "add site %p to %p\n", s, v);
+//     fprintf(stderr, "add site %p (%d) to %p\n", s, s->type(c), v);
     if (s->tryAcquire(c, stack, size, v)) {
       s->next = v->sites;
       v->sites = s;
@@ -377,7 +377,7 @@ removeSite(Context* c, Value* v, Site* s)
 {
   for (Site** p = &(v->sites); *p;) {
     if (s == *p) {
-//       fprintf(stderr, "remove site %p from %p\n", s, v);
+//       fprintf(stderr, "remove site %p (%d) from %p\n", s, s->type(c), v);
       s->release(c);
       *p = (*p)->next;
       break;
@@ -1271,6 +1271,17 @@ appendCompare(Context* c, unsigned size, Value* first, Value* second)
     CompareEvent(c, size, first, second);
 }
 
+void
+maybePreserve(Context* c, Stack* stack, unsigned size, Value* v, Site* s)
+{
+  if (v->reads->next and v->sites->next == 0) {
+    assert(c, v->sites == s);
+    Site* r = freeRegister(c, size, true);
+    addSite(c, stack, size, v, r);
+    apply(c, Move, size, s, r);    
+  }
+}
+
 class CombineEvent: public Event {
  public:
   CombineEvent(Context* c, BinaryOperation type, unsigned size, Value* first,
@@ -1295,6 +1306,8 @@ class CombineEvent: public Event {
       fprintf(stderr, "CombineEvent.compile\n");
     }
 
+    maybePreserve(c, stack, size, second, second->source);
+
     apply(c, type, size, first->source, second->source);
 
     nextRead(c, first);
@@ -1351,6 +1364,8 @@ class TranslateEvent: public Event {
       fprintf(stderr, "TranslateEvent.compile\n");
     }
 
+    maybePreserve(c, stack, size, value, value->source);
+
     apply(c, type, size, value->source);
     
     nextRead(c, value);