diff --git a/src/fastlock.cpp b/src/fastlock.cpp
index 1a8d51165..6dd2893bb 100644
--- a/src/fastlock.cpp
+++ b/src/fastlock.cpp
@@ -113,7 +113,7 @@ extern "C" int fastlock_trylock(struct fastlock *lock)
 
     struct ticket ticket_expect { active, active };
     struct ticket ticket_setiflocked { active, next };
-    if (__atomic_compare_exchange(&lock->m_ticket, &ticket_expect, &ticket_setiflocked, true /*strong*/, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE))
+    if (__atomic_compare_exchange(&lock->m_ticket, &ticket_expect, &ticket_setiflocked, false /*strong*/, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE))
     {
         lock->m_depth = 1;
         __atomic_store_4(&lock->m_pidOwner, gettid(), __ATOMIC_RELEASE);
@@ -147,4 +147,4 @@ extern "C" void fastlock_free(struct fastlock *lock)
 bool fastlock::fOwnLock()
 {
     return gettid() == m_pidOwner;
-}
\ No newline at end of file
+}