diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
index bf206ffe5c457636441aec845403e2c670f4dc88..9aff89bc75351d13353cd299b324adef99906a1b 100755
--- a/tools/perf/check-headers.sh
+++ b/tools/perf/check-headers.sh
@@ -59,6 +59,7 @@ check () {
   file=$1
 
   shift
+  opts=
   while [ -n "$*" ]; do
     opts="$opts \"$1\""
     shift