diff --git a/src/canonmn.cpp b/src/canonmn.cpp
index d5a68326..9302ebb3 100644
--- a/src/canonmn.cpp
+++ b/src/canonmn.cpp
@@ -1698,7 +1698,7 @@ namespace Exiv2 {
             // see also printSi0x0017
             std::ostringstream oss;
             oss.copyfmt(os);
-            int res = static_cast<int>(100.0 * (value.toLong() / 32.0 + 5.0) + 0.5);
+            int res = static_cast<int>(100.0 * (static_cast<short>(value.toLong()) / 32.0 + 5.0) + 0.5);
             os << std::fixed << std::setprecision(2) << res / 100.0;
             os.copyfmt(oss);
         }