diff --git a/luatex.def b/luatex.def
index 0d0db5c..5e54f70 100644
--- a/luatex.def
+++ b/luatex.def
@@ -291,7 +291,7 @@
 \def\GPT@Minus{-}
 \def\GPT@NormalizeNumber#1{%
   \edef#1{#1}%
-  \edef#1{\expandafter\zap@space\expandafter{#1}}%
+  \edef#1{\expandafter\zap@space#1 \@empty}%
   \edef#1{\expandafter\GPT@ZapPlus#1+\@nil}%
   \edef#1{\expandafter\GPT@ZapMinusMinus#1--\@nil}%
   \expandafter\GPT@Split#1..\@nil
diff --git a/pdftex.def b/pdftex.def
index c4a9424..edfcdf1 100644
--- a/pdftex.def
+++ b/pdftex.def
@@ -309,7 +309,7 @@ E     \else
 \def\GPT@Minus{-}
 \def\GPT@NormalizeNumber#1{%
   \edef#1{#1}%
-  \edef#1{\expandafter\zap@space\expandafter{#1}}%
+  \edef#1{\expandafter\zap@space#1 \@empty}%
   \edef#1{\expandafter\GPT@ZapPlus#1+\@nil}%
   \edef#1{\expandafter\GPT@ZapMinusMinus#1--\@nil}%
   \expandafter\GPT@Split#1..\@nil