diff --git a/coders/pnm.c b/coders/pnm.c
index 1dc040d..3182e56 100644
--- a/coders/pnm.c
+++ b/coders/pnm.c
@@ -304,7 +304,7 @@
               scale[MaxTextExtent];
 
             (void) ReadBlobString(image,scale);
-            quantum_scale=LocaleToDouble(scale,(char **) NULL);
+            quantum_scale=InterpretLocaleValue(scale,(char **) NULL);
           }
         else
           {