diff --git a/src/key.h b/src/key.h
index 8c2f44801..f36e658de 100644
--- a/src/key.h
+++ b/src/key.h
@@ -13,7 +13,7 @@
 #include <stdexcept>
 #include <vector>
 
-class CExtPubKey;
+struct CExtPubKey;
 class CPubKey;
 
 /**