diff --git a/src/canonmn_int.cpp b/src/canonmn_int.cpp
index 38181c5d..f17e1cd8 100644
--- a/src/canonmn_int.cpp
+++ b/src/canonmn_int.cpp
@@ -2842,9 +2842,9 @@ namespace Exiv2 {
         std::ostringstream oss;
         oss << std::fixed << std::setprecision(0);
         if (ltfl.focalLengthMin_ == ltfl.focalLengthMax_) {
-            oss << (ltfl.focalLengthMin_ / divisor) << "mm";
+            oss << " " << (ltfl.focalLengthMin_ / divisor) << "mm";
         } else {
-            oss << (ltfl.focalLengthMin_ / divisor) << "-" << (ltfl.focalLengthMax_ / divisor) << "mm";
+            oss << " " << (ltfl.focalLengthMin_ / divisor) << "-" << (ltfl.focalLengthMax_ / divisor) << "mm";
         }
         ltfl.focalLength_ = oss.str();
     }