diff --git a/src/chain.h b/src/chain.h
index e4076e00a..b7e8a9176 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -56,7 +56,7 @@ struct CDiskBlockPos
 
 };
 
-enum BlockStatus {
+enum BlockStatus: uint32_t {
     //! Unused.
     BLOCK_VALID_UNKNOWN      =    0,