diff --git a/src/system/kernel/condition_variable.cpp b/src/system/kernel/condition_variable.cpp
index 04cfc722e1..7c624ea5f4 100644
--- a/src/system/kernel/condition_variable.cpp
+++ b/src/system/kernel/condition_variable.cpp
@@ -398,17 +398,27 @@ ConditionVariable::_NotifyLocked(bool all, status_t result)
 					panic("entries count was not decremented for a long time!");
 			}
 		} else {
-			const status_t waitStatus = atomic_get_and_set(&entry->fWaitStatus, result);
+			status_t waitStatus = atomic_get_and_set(&entry->fWaitStatus, result);
 
-			// We need not waste time trying to unblock the thread if it already unblocked.
-			if (waitStatus == STATUS_WAITING && thread_is_blocked(thread))
-				thread_unblock(thread, result);
+			SpinLocker threadLocker(thread->scheduler_lock);
+			if (waitStatus == STATUS_WAITING && thread->state != B_THREAD_WAITING) {
+				// The thread is not in B_THREAD_WAITING state, so we must unblock it early,
+				// in case it tries to re-block itself immediately after we unset fVariable.
+				thread_unblock_locked(thread, result);
+				waitStatus = result;
+			}
 
 			// No matter what the thread is doing, as we were the ones to clear its
 			// fThread, so we are the ones responsible for decrementing fEntriesCount.
 			// (We may not validly access the entry once we unset its fVariable.)
 			atomic_pointer_set(&entry->fVariable, (ConditionVariable*)NULL);
 			atomic_add(&fEntriesCount, -1);
+
+			// If the thread was in B_THREAD_WAITING state, we unblock it after unsetting
+			// fVariable, because otherwise it will wake up before thread_unblock returns
+			// and spin while waiting for us to do so.
+			if (waitStatus == STATUS_WAITING)
+				thread_unblock_locked(thread, result);
 		}
 
 		if (!all)