diff --git a/src/thread/thread.c b/src/thread/thread.c
index 1acfa4c..e678e05 100644
--- a/src/thread/thread.c
+++ b/src/thread/thread.c
@@ -16,7 +16,8 @@
 #define WAS_ALLOCATED(entry) (entry->status & ALLOCATED)
 #define WAITING 0x4
 #define IS_WAITING(entry) (entry->status & WAITING)
-#define IS_WAITING_THREAD_FINISHED(entry) (((struct context_entry*)entry->retvalue)->status & FINISHED)
+#define GET_WAITING_THREAD(entry) ((struct context_entry*)entry->waiting)
+#define IS_WAITING_THREAD_FINISHED(entry) (GET_WAITING_THREAD(entry)->status & FINISHED)
 #define WAITED 0x8
 #define IS_WAITED(entry) (entry->status & WAITED)
 
@@ -24,7 +25,7 @@
 #define STACK_SIZE 4096
 #endif
 
-// Variables used to clean up everything at the end of the processes
+// Variables used to clean up everything at the end of the processus
 static char stack_for_freeing[STACK_SIZE] = {0};
 static int stack_valgrind_id = 0;
 static ucontext_t context_for_freeing;
@@ -34,6 +35,7 @@ struct context_entry {
     link; // Use to navigate inside the list
     ucontext_t context;
     thread_t id;
+    void *waiting;
     void* retvalue;
     int valgrind_id;
     char status;
@@ -136,8 +138,8 @@ int thread_join(thread_t thread, void** retval)
 {
     TRACE("Join thread %p", thread);
     struct context_entry* entry = thread;
-    // Check if the target is not already waited by an other
-    if (IS_WAITED(entry)) {
+    // Check if the target is not already waited by another
+    if (IS_WAITED(entry) || IS_WAITING(entry) && GET_WAITING_THREAD(entry) != running) {
         return -1;
     }
 
@@ -145,14 +147,13 @@ int thread_join(thread_t thread, void** retval)
         // Use status to be in waiting state
         running->status |= WAITING;
         // Use retvalue to share which thread we are currently waiting for
-        running->retvalue = entry;
+        running->waiting = entry;
         // Mark the waited thread as waited to not be waited by any other thread.
         entry->status |= WAITED;
         entry->retvalue = running;
         do {
             thread_yield();
         } while (!IS_FINISHED(entry));
-
         // Exit from waiting state
         running->status &= ~WAITING;
     }
@@ -177,7 +178,7 @@ void thread_exit(void* retval)
 {
     TRACE("Exit thread %p", running);
     print_entry(running);
-    if (running == 0) {
+    if (running == NULL) {
         exit(0);
     }
 
@@ -240,8 +241,8 @@ void __attribute__((constructor)) setup_main_thread()
 void __attribute__((destructor)) clear_last_thread()
 {
     TRACE("POST");
-    TAILQ_INSERT_HEAD(&head, running, link);
     // Running is the initial main thread. No need to switch to a static stack.
+    TAILQ_INSERT_HEAD(&head, running, link);
     if (!WAS_ALLOCATED(running)) {
         clear_context();
         exit(0);