diff --git a/include/exiv2/value.hpp b/include/exiv2/value.hpp
index 64a8ca7f..2078c6bd 100644
--- a/include/exiv2/value.hpp
+++ b/include/exiv2/value.hpp
@@ -44,6 +44,7 @@
 #include <sstream>
 #include <memory>
 #include <cstring>
+#include <climits>
 
 // *****************************************************************************
 // namespace extensions
@@ -1662,7 +1663,7 @@ namespace Exiv2 {
     template<>
     inline long ValueType<Rational>::toLong(long n) const
     {
-        ok_ = (value_[n].second != 0);
+        ok_ = (value_[n].second != 0 && INT_MIN < value_[n].first && value_[n].first < INT_MAX );
         if (!ok_) return 0;
         return value_[n].first / value_[n].second;
     }