diff --git a/base/bits.hpp b/base/bits.hpp
index 8aa036339b..03c938e55e 100644
--- a/base/bits.hpp
+++ b/base/bits.hpp
@@ -55,7 +55,7 @@ namespace bits
       if (x & 1)
         if (--i == 0)
           return j;
-    return SELECT1_ERROR;
+    return static_cast<unsigned int>(SELECT1_ERROR);
   }
 
   // Will be implemented when needed.