diff --git a/tools/ftfy.sh b/tools/ftfy.sh
index 95fd397771b83e904e5ac882d83aca8a3bca9ba8..c5cfdea54dfc4d052e21ba4156599217cbdaba26 100755
--- a/tools/ftfy.sh
+++ b/tools/ftfy.sh
@@ -34,7 +34,7 @@ vpx_style() {
          --align-pointer=name \
          --indent-preprocessor --convert-tabs --indent-labels \
          --suffix=none --quiet "$@"
-  sed -i 's/[[:space:]]\{1,\},/,/g' "$@"
+  sed -i "" 's/[[:space:]]\{1,\},/,/g' "$@"
 }