diff --git a/include/fru_reader.hpp b/include/fru_reader.hpp
index b1d21d8..f54d900 100644
--- a/include/fru_reader.hpp
+++ b/include/fru_reader.hpp
@@ -39,7 +39,7 @@
 class FRUReader
 {
   public:
-    FRUReader(ReadBlockFunc readFunc) : readFunc(std::move(readFunc))
+    explicit FRUReader(ReadBlockFunc readFunc) : readFunc(std::move(readFunc))
     {}
     // The ::read() operation here is analogous to ReadBlockFunc (with the same
     // return value semantics), but is not subject to SMBus block size