diff --git a/testssl.sh b/testssl.sh
index 45d9aa2..91e997d 100755
--- a/testssl.sh
+++ b/testssl.sh
@@ -352,7 +352,7 @@ wait_kill(){
 # determines whether the port has an HTTP service running or not (plain TLS, no STARTTLS)
 runs_HTTP() {
 	# SNI is nonsense for !HTTP but fortunately SMTP and friends don't care
-	printf "GET / HTTP/1.1\r\nHost: $NODE\r\nUser-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)\r\nAccept: text/*\r\n\r\n" | $OPENSSL s_client -quiet -connect $NODE:$PORT $SNI &>$TMPFILE &
+	printf "GET / HTTP/1.1\r\nHost: %s\r\nUser-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)\r\nAccept: text/*\r\n\r\n" "$NODE" | $OPENSSL s_client -quiet -connect $NODE:$PORT $SNI &>$TMPFILE &
 	wait_kill $! $HEADER_MAXSLEEP
 	head $TMPFILE | grep -q ^HTTP && SERVICE=HTTP
 	head $TMPFILE | grep -q SMTP && SERVICE=SMTP