diff --git a/src/drivers/SVG/Fl_SVG_File_Surface.cxx b/src/drivers/SVG/Fl_SVG_File_Surface.cxx
index 249ff0ae1a80cdebc9d8ff46d0cce7ea420e7e13..2a1439f7457a441fe981cc7a45b511201f02fd16 100644
--- a/src/drivers/SVG/Fl_SVG_File_Surface.cxx
+++ b/src/drivers/SVG/Fl_SVG_File_Surface.cxx
@@ -183,7 +183,7 @@ void Fl_SVG_Graphics_Driver::rect(int x, int y, int w, int h) {
 }
 
 void Fl_SVG_Graphics_Driver::rectf(int x, int y, int w, int h) {
-  fprintf(out_, "<rect x=\"%.3f\" y=\"%.3f\" width=\"%d\" height=\"%d\" "
+  clocale_fprintf(out_, "<rect x=\"%.3f\" y=\"%.3f\" width=\"%d\" height=\"%d\" "
           "fill=\"rgb(%u,%u,%u)\" />\n", x-.5, y-.5, w, h, red_, green_, blue_);
 }