diff --git a/src/ntstatus.h b/src/ntstatus.h
index 4eddc53..d6eb493 100644
--- a/src/ntstatus.h
+++ b/src/ntstatus.h
@@ -68,6 +68,10 @@ typedef NTSTATUS* PNTSTATUS;
 #define STATUS_PENDING ((NTSTATUS) 0x00000103L)
 #endif
 
+#ifndef STATUS_CANCELLED
+#define STATUS_CANCELLED ((NTSTATUS) 0xC0000120L)
+#endif
+
 #ifndef STATUS_SEVERITY_SUCCESS
 #define STATUS_SEVERITY_SUCCESS 0x0
 #endif