diff --git a/simgear/nasal/code.c b/simgear/nasal/code.c
index 2bf4645..61a7ae8 100644
--- a/simgear/nasal/code.c
+++ b/simgear/nasal/code.c
@@ -22,6 +22,19 @@ void printStackDEBUG(naContext ctx);
 
 struct Globals* globals = 0;
 
+extern unsigned int gRefCount,gObjCount;
+
+void registerGCTracker(TrackGCcb cb) {
+// check if globals is a valid pointer 
+if (!globals) {
+fprintf(stderr, "Globals must be set up first!)");
+return;
+}
+
+printf("Registering GC tracking callback!");
+globals->gc_cb=cb;
+}
+
 static naRef bindFunction(naContext ctx, struct Frame* f, naRef code);
 
 #define ERR(c, msg) naRuntimeError((c),(msg))
@@ -168,6 +181,8 @@ static void initGlobals()
     globals->sem = naNewSem();
     globals->lock = naNewLock();
 
+    gObjCount = gRefCount = 0;
+
     globals->allocCount = 256; // reasonable starting value
     for(i=0; i<NUM_NASAL_TYPES; i++)
         naGC_init(&(globals->pools[i]), i);
diff --git a/simgear/nasal/code.h b/simgear/nasal/code.h
index e7cb3f3..5b0befc 100644
--- a/simgear/nasal/code.h
+++ b/simgear/nasal/code.h
@@ -41,6 +41,7 @@ struct Globals {
     // Garbage collecting allocators:
     struct naPool pools[NUM_NASAL_TYPES];
     int allocCount;
+    TrackGCcb gc_cb;
 
     // Dead blocks waiting to be freed when it is safe
     void** deadBlocks;
diff --git a/simgear/nasal/gc.c b/simgear/nasal/gc.c
index 5ac9c43..6819d19 100644
--- a/simgear/nasal/gc.c
+++ b/simgear/nasal/gc.c
@@ -4,6 +4,9 @@
 
 #define MIN_BLOCK_SIZE 32
 
+int gRefCount=0;
+int gObjCount=0;
+
 static void reap(struct naPool* p);
 static void mark(naRef r);
 
@@ -38,6 +41,8 @@ static void garbageCollect()
     int i;
     struct Context* c;
     globals->allocCount = 0;
+    // https://www.mail-archive.com/flightgear-devel%40lists.sourceforge.net/msg31762.html
+    gObjCount = gRefCount=0;    
     c = globals->allContexts;
     while(c) {
         for(i=0; i<NUM_NASAL_TYPES; i++)
@@ -53,6 +58,14 @@ static void garbageCollect()
         c = c->nextAll;
     }
 
+    // check if there is a GC callback registered, if so call it
+
+    TrackGCcb cb = globals->gc_cb;
+    if(cb) {
+	// callback is registered, so call it
+	(*cb) (gRefCount, gObjCount);
+    }
+
     mark(globals->save);
     mark(globals->save_hash);
     mark(globals->symbols);
@@ -242,6 +255,7 @@ static void markvec(naRef r)
 static void mark(naRef r)
 {
     int i;
+    gRefCount ++;
 
     if(IS_NUM(r) || IS_NIL(r))
         return;
@@ -249,6 +263,8 @@ static void mark(naRef r)
     if(PTR(r).obj->mark == 1)
         return;
 
+    gObjCount++;
+
     PTR(r).obj->mark = 1;
     switch(PTR(r).obj->type) {
     case T_VEC: markvec(r); break;
diff --git a/simgear/nasal/nasal.h b/simgear/nasal/nasal.h
index 8b6b2c9..48ed460 100644
--- a/simgear/nasal/nasal.h
+++ b/simgear/nasal/nasal.h
@@ -44,6 +44,10 @@ void* naGetUserData(naContext c) GCC_PURE;
 
 // run GC now (may block)
 void naGC();
+struct Globals;
+typedef void (*TrackGCcb) (unsigned int refs, unsigned int objects);
+void registerGCTracker(TrackGCcb cb); 
+
 
 // "Save" this object in the context, preventing it (and objects
 // referenced by it) from being garbage collected.