1 files changed, 2 insertions, 2 deletions
diff --git a/misc/optvec.hpp b/misc/optvec.hpp
index d950c5f..2e8ecb2 100644
--- a/misc/optvec.hpp
+++ b/misc/optvec.hpp
@@ -13,8 +13,8 @@ namespace opt_utilities
   public:
     optvec()
     {}
-
-    optvec(size_t s)
+    
+    explicit optvec(size_t s)
       :std::vector<T>(s)
     {}