diff --git a/moo/lib/gc.c b/moo/lib/gc.c
index fea148b..50527de 100644
--- a/moo/lib/gc.c
+++ b/moo/lib/gc.c
@@ -846,20 +846,19 @@ static MOO_INLINE void gc_mark_root (moo_t* moo)
 	moo_oow_t i, gcfin_count;
 	moo_evtcb_t* cb;
 
-	if (moo->active_context)
+	if (moo->processor && moo->processor->active)
 	{
 		MOO_ASSERT (moo, (moo_oop_t)moo->processor != moo->_nil);
 		MOO_ASSERT (moo, (moo_oop_t)moo->processor->active != moo->_nil);
-		
+
 		/* commit the stack pointer to the active process because
-		 * gc utilizes the stack pointer of a process object when marking */
-		
+		 * gc needs the correct stack pointer for a process object */
 		moo->processor->active->sp = MOO_SMOOI_TO_OOP(moo->sp);
+	}
 
 	#if 0
-		moo->active_context->ip = MOO_SMOOI_TO_OOP(moo->ip); /* not needed but do it */
+	if (moo->active_context) moo->active_context->ip = MOO_SMOOI_TO_OOP(moo->ip); /* no need to commit the instruction pointer */
 	#endif
-	}
 
 	gc_mark (moo, moo->_nil);
 	gc_mark (moo, moo->_true);
diff --git a/moo/lib/obj.c b/moo/lib/obj.c
index 6377eaf..281ea96 100644
--- a/moo/lib/obj.c
+++ b/moo/lib/obj.c
@@ -34,7 +34,8 @@ void* moo_allocbytes (moo_t* moo, moo_oow_t size)
 #endif
 
 #if defined(MOO_BUILD_DEBUG)
-	if ((moo->option.trait & MOO_TRAIT_DEBUG_GC) && !(moo->option.trait & MOO_TRAIT_NOGC)) moo_gc (moo);
+	/* DEBUG_GC is set but NOGC is not set */
+	if ((moo->option.trait & (MOO_TRAIT_DEBUG_GC | MOO_TRAIT_NOGC)) == MOO_TRAIT_DEBUG_GC) moo_gc (moo);
 #endif
 
 #if defined(MOO_ENABLE_GC_MARK_SWEEP)