diff --git a/include/core/frame/frame_base.h b/include/core/frame/frame_base.h
index f9ccafdea7639dcc67769016e31cb8fc1924cb92..1b368bf02df6a89567d90455edba72cf02f54bf0 100644
--- a/include/core/frame/frame_base.h
+++ b/include/core/frame/frame_base.h
@@ -13,7 +13,7 @@ class StateBlock;
  */
 typedef enum
 {
-    KEY = 2,          ///< key frame. It plays at optimizations (estimated).
+    KEY = 1,          ///< key frame. It plays at optimizations (estimated).
     // AUXILIARY = 1,    ///< auxiliary frame. It plays at optimizations (estimated).
     NON_ESTIMATED = 0 ///< regular frame. It does not play at optimization.
 } FrameType;