diff --git a/t/t5559-http-fetch-smart-http2.sh b/t/t5559-http-fetch-smart-http2.sh
index 9eece71c2c..54aa9d3bff 100755
--- a/t/t5559-http-fetch-smart-http2.sh
+++ b/t/t5559-http-fetch-smart-http2.sh
@@ -1,4 +1,5 @@
 #!/bin/sh
 
 HTTP_PROTO=HTTP/2
+LIB_HTTPD_SSL=1
 . ./t5551-http-fetch-smart.sh