diff --git a/crc.h b/crc.h
index 44e0e2f7..b1f5a34c 100644
--- a/crc.h
+++ b/crc.h
@@ -47,6 +47,7 @@ private:
 
 //! \brief CRC-32C Checksum Calculation
 //! \details Uses CRC polynomial 0x82F63B78
+//! \since Crypto++ 5.6.4
 class CRC32C : public HashTransformation
 {
 public: