diff --git a/build/preprocess.sh b/build/preprocess.sh
index bdee8f0e..143ef861 100755
--- a/build/preprocess.sh
+++ b/build/preprocess.sh
@@ -39,4 +39,6 @@ if [ $1 = "stripped" ]; then FLAGS="-c"; else FLAGS=""; fi
 
 eval "$COMMAND $FLAGS" > $4
 # Now convert 4 spaces to tabs, to shave of some bytes (quite a few KB actually)
-unexpand -t 4 $4 > "$4-tabs" && mv "$4-tabs" $4
+unexpand -t 4 -a $4 > "$4-tabs" && mv "$4-tabs" $4
+# Remove trailing white-space on each line
+perl -p -i -e "s/[ \t]*$//g" $4