diff --git a/Makefile b/Makefile
index 982bba6..bd38880 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ bins+=23-create-many-once
 bins+=31-switch-many
 bins+=32-switch-many-join
 bins+=33-switch-many-cascade
-bins+=51-fibonacci
+#bins+=51-fibonacci
 bins+=61-mutex
 bins+=62-mutex
 bins+=63-mutex-equity
@@ -25,6 +25,7 @@ bins+=81-deadlock
 
 bins_target=$(addprefix ${build_dir}/,${bins})
 install_bins_targets=$(addprefix ${install_dir}/bin/,${bins})
+install_bins_targets+=${install_dir}/bin/51-fibonacci
 
 valgrind_targets=$(addprefix valgrind_,${bins})
 
@@ -108,6 +109,9 @@ check: ${check_targets}
 ${check_targets}: check_%: ${build_dir}/%
 	$^ ${check_argv}
 
+${build_dir}/51-fibonacci: ${build_dir}/src/thread/thread_fibo.o ${build_dir}/${tst_dir}/51-fibonacci.o
+	${CC} -o $@ $^ ${CFLAGS}   ./lib/libmimalloc ${LDFLAGS}
+
 ${bins_target}: ${build_dir}/%: ${objs} ${build_dir}/${tst_dir}/%.o
 	${CC} -o $@ $^ ${CFLAGS}   ./lib/libmimalloc ${LDFLAGS}
 
@@ -117,6 +121,10 @@ ${build_dir}/libthread.so: ${objs}
 ${build_dir}/libthread.a: ${objs}
 	ar rcs $@ $^
 
+${build_dir}/%_fibo.o: %.c
+	@mkdir -p $(dir $@)
+	${CC} -o $@ -c $^ -DFIBO_STRAT ${CFLAGS}
+
 ${build_dir}/%.o: %.c
 	@mkdir -p $(dir $@)
 	${CC} -o $@ -c $^ ${CFLAGS}
diff --git a/src/thread/thread.c b/src/thread/thread.c
index eeff5bb..5b71e06 100644
--- a/src/thread/thread.c
+++ b/src/thread/thread.c
@@ -24,6 +24,13 @@
 #define IS_WAITED(entry) (HAS_STATUS(entry, WAITED))
 #define IS_MUTEX_WAITING(entry) (HAS_STATUS(entry, MUTEX_WAITING))
 
+#ifdef FIBO_STRAT
+
+#define YIELD 0x20
+#define IS_YIELD(entry) (HAS_STATUS(entry, YIELD))
+
+#endif
+
 #ifndef STACK_SIZE
 #define STACK_SIZE 4096
 #endif
@@ -83,6 +90,13 @@ int thread_yield(void)
         return 0;
     }
 
+#ifdef FIBO_STRAT
+    if (!(IS_YIELD(running)) && !IS_FINISHED(running) && !IS_WAITING(running)) {
+        SET_STATUS(running, YIELD);
+        return 0;
+    }
+#endif
+
     /* Current strategy :
      * if we have checked the number of threads then keep the running one
      * otherwise, take the first element of the list should not be null
@@ -157,7 +171,11 @@ int thread_create(thread_t* newthread, void* (*func)(void*), void* funcarg)
 
     makecontext(&new_entry->context, (void (*)(void))thread_function_wrapper, 2, func, funcarg);
 
+#ifdef FIBO_STRAT
+    TAILQ_INSERT_HEAD(&head, new_entry, link);
+#else
     TAILQ_INSERT_TAIL(&head, new_entry, link);
+#endif
     return 0;
 }
 
@@ -224,10 +242,14 @@ int thread_join(thread_t thread, void** retval)
   
 
         DBG("%p is waiting for %p", running, entry);
+        DBG("MUTEX WAITING %d", IS_MUTEX_WAITING(GET_LAST_WAITED_THREAD(running)));
+#ifdef FIBO_STRAT
+#else
         if (!IS_MUTEX_WAITING(GET_LAST_WAITED_THREAD(running))) {
           TAILQ_REMOVE(&head, GET_LAST_WAITED_THREAD(running), link);
           TAILQ_INSERT_HEAD(&head, GET_LAST_WAITED_THREAD(running), link);
         }
+#endif
         do {
             thread_yield();
         } while (!IS_FINISHED(entry));
@@ -271,7 +293,11 @@ void thread_exit(void* retval)
     if (IS_WAITED(running)) {
         // If the thread was waited by another thread, we need to wake it up.
         struct context_entry* waited = running->retvalue;
+#ifdef FIBO_STRAT
+        TAILQ_INSERT_HEAD(&head, waited, link);
+#else
         TAILQ_INSERT_TAIL(&head, waited, link);
+#endif
     }
     running->retvalue = retval;
 
@@ -332,6 +358,7 @@ void __attribute__((constructor)) setup_main_thread()
     // memset(main, 0, sizeof(*main));
     getcontext(&main->context);
     main->status = 0;
+    main->valgrind_id = 0;
     main->retvalue = NULL;
     main->last_waited = NULL;
     main->mutex_fifo_entry = NULL;