diff --git a/coders/jpeg.c b/coders/jpeg.c
index 65549e5..18d630e 100644
--- a/coders/jpeg.c
+++ b/coders/jpeg.c
@@ -1991,7 +1991,7 @@
             Search for compression quality that does not exceed image extent.
           */
           jpeg_info->quality=0;
-          extent=(MagickSizeType) InterpretLocaleInterval(option,100.0);
+          extent=(MagickSizeType) StringToDoubleInterval(option,100.0);
           (void) DeleteImageOption(jpeg_info,"jpeg:extent");
           (void) AcquireUniqueFilename(jpeg_image->filename);
           maximum=101;