diff --git a/evthread_win32.c b/evthread_win32.c
index ad055107a4..995e0e151f 100644
--- a/evthread_win32.c
+++ b/evthread_win32.c
@@ -53,6 +53,7 @@ evthread_win32_lock_free(void *_lock, unsigned locktype)
 {
 	CRITICAL_SECTION *lock = _lock;
 	DeleteCriticalSection(lock);
+	mm_free(lock);
 }
 
 static int