diff --git a/src/wic/ksparser.py b/src/wic/ksparser.py
index 24c7015b336d..a73ae56cd196 100644
--- a/src/wic/ksparser.py
+++ b/src/wic/ksparser.py
@@ -99,7 +99,7 @@ def overheadtype(arg):
         raise ArgumentTypeError("Invalid value: %r" % arg)
 
     if result < 1.0:
-        raise ArgumentTypeError("Overhead factor should be > 1.0" % arg)
+        raise ArgumentTypeError("Overhead factor should be > 1.0, not %r" % arg)
 
     return result